645164 has 24 divisors (see below), whose sum is σ = 1281840. Its totient is φ = 281664.

The previous prime is 645149. The next prime is 645179. The reversal of 645164 is 461546.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (645149) and next prime (645179).

It is a Harshad number since it is a multiple of its sum of digits (26).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645164.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 662 + ... + 1314.

It is an arithmetic number, because the mean of its divisors is an integer number (53410).

2⁶⁴⁵¹⁶⁴ is an apocalyptic number.

It is an amenable number.

645164 is a deficient number, since it is larger than the sum of its proper divisors (636676).

645164 is a wasteful number, since it uses less digits than its factorization.

645164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 689 (or 687 counting only the distinct ones).

The product of its digits is 2880, while the sum is 26.

The square root of 645164 is about 803.2210156613. The cubic root of 645164 is about 86.4085482512.

It can be divided in two parts, 64516 and 4, that multiplied together give a square (258064 = 508²).

The spelling of 645164 in words is "six hundred forty-five thousand, one hundred sixty-four".