621644131 has 4 divisors (see below), whose sum is σ = 622007064. Its totient is φ = 621281200.

The previous prime is 621644059. The next prime is 621644171. The reversal of 621644131 is 131446126.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 621644131 - 2⁷ = 621644003 is a prime.

It is a super-2 number, since 2×621644131² = 772882851213490322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 621644131.

It is not an unprimeable number, because it can be changed into a prime (621644171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 178885 + ... + 182326.

It is an arithmetic number, because the mean of its divisors is an integer number (155501766).

Almost surely, 2^621644131 is an apocalyptic number.

621644131 is a deficient number, since it is larger than the sum of its proper divisors (362933).

621644131 is a wasteful number, since it uses less digits than its factorization.

621644131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362932.

The product of its digits is 3456, while the sum is 28.

The square root of 621644131 is about 24932.7922824540. The cubic root of 621644131 is about 853.4549715553.

The spelling of 621644131 in words is "six hundred twenty-one million, six hundred forty-four thousand, one hundred thirty-one".