625531631 has 4 divisors (see below), whose sum is σ = 634867992. Its totient is φ = 616195272.

The previous prime is 625531589. The next prime is 625531639. The reversal of 625531631 is 136135526.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-625531631 is a prime.

It is a super-2 number, since 2×625531631² = 782579642763040322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (625531639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4668080 + ... + 4668213.

It is an arithmetic number, because the mean of its divisors is an integer number (158716998).

Almost surely, 2^625531631 is an apocalyptic number.

625531631 is a deficient number, since it is larger than the sum of its proper divisors (9336361).

625531631 is an equidigital number, since it uses as much as digits as its factorization.

625531631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9336360.

The product of its digits is 16200, while the sum is 32.

The square root of 625531631 is about 25010.6303599090. The cubic root of 625531631 is about 855.2303249618.

The spelling of 625531631 in words is "six hundred twenty-five million, five hundred thirty-one thousand, six hundred thirty-one".