645252 has 24 divisors (see below), whose sum is σ = 1594656. Its totient is φ = 202368.

The previous prime is 645233. The next prime is 645257. The reversal of 645252 is 252546.

645252 is nontrivially palindromic in base 15.

It is not an unprimeable number, because it can be changed into a prime (645257) by changing a digit.

645252 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 7 ways as a sum of consecutive naturals, for example, 1378 + ... + 1785.

It is an arithmetic number, because the mean of its divisors is an integer number (66444).

2⁶⁴⁵²⁵² is an apocalyptic number.

It is an amenable number.

645252 is an abundant number, since it is smaller than the sum of its proper divisors (949404).

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

645252 is a wasteful number, since it uses less digits than its factorization.

645252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3187 (or 3185 counting only the distinct ones).

The product of its digits is 2400, while the sum is 24.

The square root of 645252 is about 803.2757932367. The cubic root of 645252 is about 86.4124767647.

Adding to 645252 its reverse (252546), we get a palindrome (897798).

The spelling of 645252 in words is "six hundred forty-five thousand, two hundred fifty-two".