645667637064 has 32 divisors (see below), whose sum is σ = 1618794240000. Its totient is φ = 214605859392.

The previous prime is 645667636987. The next prime is 645667637071. The reversal of 645667637064 is 460736766546.

It is a junction number, because it is equal to n+sod(n) for n = 645667636989 and 645667637007.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 38534344 + ... + 38551095.

It is an arithmetic number, because the mean of its divisors is an integer number (50587320000).

Almost surely, 2^645667637064 is an apocalyptic number.

It is an amenable number.

645667637064 is an abundant number, since it is smaller than the sum of its proper divisors (973126602936).

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

645667637064 is a wasteful number, since it uses less digits than its factorization.

645667637064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77085797 (or 77085793 counting only the distinct ones).

The product of its (nonzero) digits is 91445760, while the sum is 60.

The spelling of 645667637064 in words is "six hundred forty-five billion, six hundred sixty-seven million, six hundred thirty-seven thousand, sixty-four".