645276 has 12 divisors (see below), whose sum is σ = 1505672. Its totient is φ = 215088.

The previous prime is 645257. The next prime is 645313. The reversal of 645276 is 672546.

645276 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 (12).

It is a super-2 number, since 2×645276² = 832762232352, which contains 22 as substring.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

645276 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26875 + ... + 26898.

2⁶⁴⁵²⁷⁶ is an apocalyptic number.

It is an amenable number.

645276 is an abundant number, since it is smaller than the sum of its proper divisors (860396).

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

645276 is a wasteful number, since it uses less digits than its factorization.

645276 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53780 (or 53778 counting only the distinct ones).

The product of its digits is 10080, while the sum is 30.

The square root of 645276 is about 803.2907319271. The cubic root of 645276 is about 86.4135481155.

The spelling of 645276 in words is "six hundred forty-five thousand, two hundred seventy-six".