621639431 has 12 divisors (see below), whose sum is σ = 724041360. Its totient is φ = 532163520.

The previous prime is 621639419. The next prime is 621639439. The reversal of 621639431 is 134936126.

It is a happy number.

621639431 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-621639431 is a prime.

It is a super-2 number, since 2×621639431² = 772871164348007522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 621639391 and 621639400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621639439) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 33551 + ... + 48671.

It is an arithmetic number, because the mean of its divisors is an integer number (60336780).

Almost surely, 2^621639431 is an apocalyptic number.

621639431 is a deficient number, since it is larger than the sum of its proper divisors (102401929).

621639431 is a wasteful number, since it uses less digits than its factorization.

621639431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15974 (or 15967 counting only the distinct ones).

The product of its digits is 23328, while the sum is 35.

The square root of 621639431 is about 24932.6980288937. The cubic root of 621639431 is about 853.4528206738.

The spelling of 621639431 in words is "six hundred twenty-one million, six hundred thirty-nine thousand, four hundred thirty-one".