Properties of the Number 21638

Twenty-One Thousand Six Hundred Thirty-Eight

Basics

Value: 21637 → 21638 → 21639

Parity: even

Prime: No

Previous Prime: 21617

Next Prime: 21647

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 2 × 31 × 349

Divisors: 1, 2, 31, 62, 349, 698, 10819, 21638

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010010000110

Octal: 52206

Duodecimal: 10632

Hexadecimal: 5486

Square: 468203044

Square Root: 147.09860638360922

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: No

Perfect Number: No

Special

Kaprekar Constant: No

Munchausen Constant: No

Armstrong Number: No

Kaprekar Number: No

Catalan Number: No

Vampire Number: No

Taxicab Number: No

Super Prime: No

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

Numbers k such that (7·10^k + 71)/3 is prime. A270831

a(n) = ∑_d∣n p(d), where p(d) = A000041 = number of partitions of d. A47968

Number of partitions of partitions of n where all partitions have the same sum. A305551

Twice-partitioned numbers where the first partition is constant. A279787

Number of ways to split an integer partition of n into consecutive subsequences with equal sums. A317715

Number of non-isomorphic set multipartitions of weight n in which all parts have the same size. A306018

a(n) = 1 + (number of partitions of n, n>0). A52810

Irregular table read by rows: T(n,k) is the number of permutations in S_n that have exactly k occurrences of the pattern 2413. 0 <= k <= A342854(n). A342860

Number of rectangular twice-partitions of n of type (P,R,P). A358833

Number of series-reduced planted achiral trees whose leaves span an initial interval of positive integers appearing with multiplicities an integer partition of n. A317099