640348770 has 32 divisors (see below), whose sum is σ = 1554111360. Its totient is φ = 168840320.

The previous prime is 640348769. The next prime is 640348789. The reversal of 640348770 is 77843046.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117246 + ... + 122585.

It is an arithmetic number, because the mean of its divisors is an integer number (48565980).

Almost surely, 2^640348770 is an apocalyptic number.

640348770 is an abundant number, since it is smaller than the sum of its proper divisors (913762590).

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

640348770 is a wasteful number, since it uses less digits than its factorization.

640348770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239930.

The product of its (nonzero) digits is 112896, while the sum is 39.

The square root of 640348770 is about 25305.1135148610. The cubic root of 640348770 is about 861.9303897076.

The spelling of 640348770 in words is "six hundred forty million, three hundred forty-eight thousand, seven hundred seventy".