645232 has 30 divisors (see below), whose sum is σ = 1456008. Its totient is φ = 276192.

The previous prime is 645187. The next prime is 645233. The reversal of 645232 is 232546.

It is a happy number.

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645233) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 373 + ... + 1195.

2⁶⁴⁵²³² 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 645232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (728004).

645232 is an abundant number, since it is smaller than the sum of its proper divisors (810776).

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

645232 is a wasteful number, since it uses less digits than its factorization.

645232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 845 (or 832 counting only the distinct ones).

The product of its digits is 1440, while the sum is 22.

The square root of 645232 is about 803.2633441157. The cubic root of 645232 is about 86.4115839521.

Adding to 645232 its reverse (232546), we get a palindrome (877778).

Subtracting from 645232 its reverse (232546), we obtain a triangular number (412686 = T₉₀₈).

The spelling of 645232 in words is "six hundred forty-five thousand, two hundred thirty-two".