64431623560 has 32 divisors (see below), whose sum is σ = 145099661400. Its totient is φ = 25749803520.

The previous prime is 64431623527. The next prime is 64431623629. The reversal of 64431623560 is 6532613446.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 40932573124 + 23499050436 = 202318^2 + 153294^2 .

It is a super-2 number, since 2×64431623560² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 668211 + ... + 758530.

Almost surely, 2^64431623560 is an apocalyptic number.

It is an amenable number.

64431623560 is an abundant number, since it is smaller than the sum of its proper divisors (80668037840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

64431623560 is a wasteful number, since it uses less digits than its factorization.

64431623560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1427881 (or 1427877 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 40.

The spelling of 64431623560 in words is "sixty-four billion, four hundred thirty-one million, six hundred twenty-three thousand, five hundred sixty".