64631431 has 2 divisors, whose sum is σ = 64631432. Its totient is φ = 64631430.

The previous prime is 64631423. The next prime is 64631447. The reversal of 64631431 is 13413646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64631431 - 2³ = 64631423 is a prime.

It is a super-2 number, since 2×64631431² = 8354443746215522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 64631431.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64631471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32315715 + 32315716.

It is an arithmetic number, because the mean of its divisors is an integer number (32315716).

Almost surely, 2^64631431 is an apocalyptic number.

64631431 is a deficient number, since it is larger than the sum of its proper divisors (1).

64631431 is an equidigital number, since it uses as much as digits as its factorization.

64631431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 28.

The square root of 64631431 is about 8039.3675746292. The cubic root of 64631431 is about 401.3111785806.

The spelling of 64631431 in words is "sixty-four million, six hundred thirty-one thousand, four hundred thirty-one".