640091520 has 96 divisors (see below), whose sum is σ = 2210335920. Its totient is φ = 170689536.

The previous prime is 640091519. The next prime is 640091533. The reversal of 640091520 is 25190046.

640091520 is a `hidden beast` number, since 640 + 0 + 9 + 15 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

640091520 is a modest number, since divided by 91520 gives 640 as remainder.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 49804 + ... + 61323.

Almost surely, 2^640091520 is an apocalyptic number.

640091520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

640091520 is an abundant number, since it is smaller than the sum of its proper divisors (1570244400).

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

640091520 is a wasteful number, since it uses less digits than its factorization.

640091520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111152 (or 111137 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 640091520 is about 25300.0300395079. The cubic root of 640091520 is about 861.8149519430.

The spelling of 640091520 in words is "six hundred forty million, ninety-one thousand, five hundred twenty".