645592920 has 64 divisors (see below), whose sum is σ = 2213464320. Its totient is φ = 147563904.

The previous prime is 645592919. The next prime is 645592933. The reversal of 645592920 is 29295546.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent 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, 383442 + ... + 385121.

It is an arithmetic number, because the mean of its divisors is an integer number (34585380).

Almost surely, 2^645592920 is an apocalyptic number.

645592920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

645592920 is an abundant number, since it is smaller than the sum of its proper divisors (1567871400).

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

645592920 is a wasteful number, since it uses less digits than its factorization.

645592920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 768584 (or 768580 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 42.

The square root of 645592920 is about 25408.5206180919. The cubic root of 645592920 is about 864.2769281195.

The spelling of 645592920 in words is "six hundred forty-five million, five hundred ninety-two thousand, nine hundred twenty".