64623531640 has 32 divisors (see below), whose sum is σ = 145451700000. Its totient is φ = 25840745344.

The previous prime is 64623531619. The next prime is 64623531653. The reversal of 64623531640 is 4613532646.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 64623531593 and 64623531602.

It is a congruent number.

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, 149395 + ... + 389314.

It is an arithmetic number, because the mean of its divisors is an integer number (4545365625).

Almost surely, 2^64623531640 is an apocalyptic number.

It is an amenable number.

64623531640 is an abundant number, since it is smaller than the sum of its proper divisors (80828168360).

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

64623531640 is a wasteful number, since it uses less digits than its factorization.

64623531640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 541719 (or 541715 counting only the distinct ones).

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

The spelling of 64623531640 in words is "sixty-four billion, six hundred twenty-three million, five hundred thirty-one thousand, six hundred forty".