645442165 has 16 divisors (see below), whose sum is σ = 800501760. Its totient is φ = 499080960.

The previous prime is 645442157. The next prime is 645442177. The reversal of 645442165 is 561244546.

It is not a de Polignac number, because 645442165 - 2³ = 645442157 is a prime.

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, 154332 + ... + 158458.

It is an arithmetic number, because the mean of its divisors is an integer number (50031360).

Almost surely, 2^645442165 is an apocalyptic number.

It is an amenable number.

645442165 is a deficient number, since it is larger than the sum of its proper divisors (155059595).

645442165 is a wasteful number, since it uses less digits than its factorization.

645442165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5172.

The product of its digits is 115200, while the sum is 37.

The square root of 645442165 is about 25405.5538219500. The cubic root of 645442165 is about 864.2096492882.

The spelling of 645442165 in words is "six hundred forty-five million, four hundred forty-two thousand, one hundred sixty-five".