640456770 has 32 divisors (see below), whose sum is σ = 1566101952. Its totient is φ = 167565632.

The previous prime is 640456757. The next prime is 640456783. The reversal of 640456770 is 77654046.

It is an interprime number because it is at equal distance from previous prime (640456757) and next prime (640456783).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 199812 + ... + 202991.

It is an arithmetic number, because the mean of its divisors is an integer number (48940686).

Almost surely, 2^640456770 is an apocalyptic number.

640456770 is an abundant number, since it is smaller than the sum of its proper divisors (925645182).

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

640456770 is a wasteful number, since it uses less digits than its factorization.

640456770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 402866.

The product of its (nonzero) digits is 141120, while the sum is 39.

The square root of 640456770 is about 25307.2473809381. The cubic root of 640456770 is about 861.9788441611.

The spelling of 640456770 in words is "six hundred forty million, four hundred fifty-six thousand, seven hundred seventy".