645372 has 72 divisors (see below), whose sum is σ = 2018016. Its totient is φ = 169344.

The previous prime is 645367. The next prime is 645383. The reversal of 645372 is 273546.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3178 + ... + 3374.

It is an arithmetic number, because the mean of its divisors is an integer number (28028).

2⁶⁴⁵³⁷² is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645372, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1009008).

645372 is an abundant number, since it is smaller than the sum of its proper divisors (1372644).

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

645372 is a wasteful number, since it uses less digits than its factorization.

645372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227 (or 222 counting only the distinct ones).

The product of its digits is 5040, while the sum is 27.

The square root of 645372 is about 803.3504839110. The cubic root of 645372 is about 86.4178332531.

The spelling of 645372 in words is "six hundred forty-five thousand, three hundred seventy-two".