64615631 has 4 divisors (see below), whose sum is σ = 66191664. Its totient is φ = 63039600.

The previous prime is 64615597. The next prime is 64615633. The reversal of 64615631 is 13651646.

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-64615631 is a prime.

It is a super-2 number, since 2×64615631² = 8350359539056322, 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 (64615633) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 787955 + ... + 788036.

It is an arithmetic number, because the mean of its divisors is an integer number (16547916).

Almost surely, 2^64615631 is an apocalyptic number.

64615631 is a deficient number, since it is larger than the sum of its proper divisors (1576033).

64615631 is a wasteful number, since it uses less digits than its factorization.

64615631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1576032.

The product of its digits is 12960, while the sum is 32.

The square root of 64615631 is about 8038.3848502047. The cubic root of 64615631 is about 401.2784739905.

The spelling of 64615631 in words is "sixty-four million, six hundred fifteen thousand, six hundred thirty-one".