640040664064 has 44 divisors (see below), whose sum is σ = 1310662625328. Its totient is φ = 312214937600.

The previous prime is 640040664019. The next prime is 640040664071. The reversal of 640040664064 is 460466040046.

It is a happy number.

It is a super-2 number, since 2×640040664064² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7580452 + ... + 7664419.

Almost surely, 2^640040664064 is an apocalyptic number.

640040664064 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

640040664064 is an abundant number, since it is smaller than the sum of its proper divisors (670621961264).

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

640040664064 is a wasteful number, since it uses less digits than its factorization.

640040664064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15244932 (or 15244914 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 40.

The spelling of 640040664064 in words is "six hundred forty billion, forty million, six hundred sixty-four thousand, sixty-four".