645442164 has 36 divisors (see below), whose sum is σ = 1666252224. Its totient is φ = 210569232.

The previous prime is 645442157. The next prime is 645442177. The reversal of 645442164 is 461244546.

645442164 is a `hidden beast` number, since 6 + 454 + 42 + 164 = 666.

645442164 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 189042 + ... + 192425.

It is an arithmetic number, because the mean of its divisors is an integer number (46284784).

Almost surely, 2^645442164 is an apocalyptic number.

It is an amenable number.

645442164 is an abundant number, since it is smaller than the sum of its proper divisors (1020810060).

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

645442164 is a wasteful number, since it uses less digits than its factorization.

645442164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381524 (or 381519 counting only the distinct ones).

The product of its digits is 92160, while the sum is 36.

The square root of 645442164 is about 25405.5538022693. The cubic root of 645442164 is about 864.2096488419.

The spelling of 645442164 in words is "six hundred forty-five million, four hundred forty-two thousand, one hundred sixty-four".