640265340 has 96 divisors (see below), whose sum is σ = 2106187776. Its totient is φ = 143274240.

The previous prime is 640265273. The next prime is 640265357. The reversal of 640265340 is 43562046.

640265340 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 640265298 and 640265307.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28732 + ... + 45891.

It is an arithmetic number, because the mean of its divisors is an integer number (21939456).

Almost surely, 2^640265340 is an apocalyptic number.

640265340 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

640265340 is an abundant number, since it is smaller than the sum of its proper divisors (1465922436).

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

640265340 is a wasteful number, since it uses less digits than its factorization.

640265340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74659 (or 74657 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 30.

The square root of 640265340 is about 25303.4649801169. The cubic root of 640265340 is about 861.8929549121.

The spelling of 640265340 in words is "six hundred forty million, two hundred sixty-five thousand, three hundred forty".