Properties of the Number 1621

One Thousand Six Hundred Twenty-One

Basics

Value: 1620 → 1621 → 1622

Parity: odd

Prime: Yes

Previous Prime: 1619

Next Prime: 1627

Digit Sum: 10

Digital Root: 1

Palindrome: No

Factorization: 1621

Divisors: 1, 1621

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 11001010101

Octal: 3125

Duodecimal: B31

Hexadecimal: 655

Square: 2627641

Square Root: 40.26164427839479

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: Yes

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

Primes p such that (p+1)/2 is prime. A5383

Number of "ON" cells at n-th stage in the "Ulam-Warburton" two-dimensional cellular automaton. A147562

Numbers k such that the k-th partition number A000041(k) is prime. A46063

Primes that become a different prime under the mapping 0 <=> 2. A180517

Primes p whose base-3 expansion is also the decimal expansion of a prime. A65721

Finitary primes. Primes of finitary index. A277098

a(n) = 4·n² - 7·n + 4. A54567

Primes of the form x² + 45y². A107152

Dispersion of A016813 (4k+1, k>1), by antidiagonals. A191667

Primes prime(k) for which A049076(k) = 2. A49078