640437377064 has 32 divisors (see below), whose sum is σ = 1601221380000. Its totient is φ = 213462067392.

The previous prime is 640437377059. The next prime is 640437377081. The reversal of 640437377064 is 460773734046.

It is a super-2 number, since 2×640437377064² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 640437376998 and 640437377016.

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, 757714 + ... + 1361985.

It is an arithmetic number, because the mean of its divisors is an integer number (50038168125).

Almost surely, 2^640437377064 is an apocalyptic number.

It is an amenable number.

640437377064 is an abundant number, since it is smaller than the sum of its proper divisors (960784002936).

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

640437377064 is a wasteful number, since it uses less digits than its factorization.

640437377064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2132297 (or 2132293 counting only the distinct ones).

The product of its (nonzero) digits is 7112448, while the sum is 51.

The spelling of 640437377064 in words is "six hundred forty billion, four hundred thirty-seven million, three hundred seventy-seven thousand, sixty-four".