721675631 has 2 divisors, whose sum is σ = 721675632. Its totient is φ = 721675630.

The previous prime is 721675627. The next prime is 721675657. The reversal of 721675631 is 136576127.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 721675631 - 2² = 721675627 is a prime.

It is a super-2 number, since 2×721675631² = 1041631432758496322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721675231) 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 as a sum of consecutive naturals, namely, 360837815 + 360837816.

It is an arithmetic number, because the mean of its divisors is an integer number (360837816).

Almost surely, 2^721675631 is an apocalyptic number.

721675631 is a deficient number, since it is larger than the sum of its proper divisors (1).

721675631 is an equidigital number, since it uses as much as digits as its factorization.

721675631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 52920, while the sum is 38.

The square root of 721675631 is about 26864.0211249172. The cubic root of 721675631 is about 896.9757051403.

The spelling of 721675631 in words is "seven hundred twenty-one million, six hundred seventy-five thousand, six hundred thirty-one".