621629 has 2 divisors, whose sum is σ = 621630. Its totient is φ = 621628.

The previous prime is 621619. The next prime is 621631. The reversal of 621629 is 926126.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 348100 + 273529 = 590^2 + 523^2 .

It is a cyclic number.

It is not a de Polignac number, because 621629 - 2¹⁶ = 556093 is a prime.

It is a super-2 number, since 2×621629² = 772845227282, which contains 22 as substring.

Together with 621631, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 621598 and 621607.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310814 + 310815.

It is an arithmetic number, because the mean of its divisors is an integer number (310815).

2⁶²¹⁶²⁹ is an apocalyptic number.

It is an amenable number.

621629 is a deficient number, since it is larger than the sum of its proper divisors (1).

621629 is an equidigital number, since it uses as much as digits as its factorization.

621629 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 26.

The square root of 621629 is about 788.4345248656. The cubic root of 621629 is about 85.3448047051.

The spelling of 621629 in words is "six hundred twenty-one thousand, six hundred twenty-nine".