645312 has 28 divisors (see below), whose sum is σ = 1707896. Its totient is φ = 215040.

The previous prime is 645257. The next prime is 645313. The reversal of 645312 is 213546.

It is a happy number.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (645313) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1489 + ... + 1872.

2⁶⁴⁵³¹² is an apocalyptic number.

It is an amenable number.

645312 is an abundant number, since it is smaller than the sum of its proper divisors (1062584).

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

645312 is a wasteful number, since it uses less digits than its factorization.

645312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3376 (or 3366 counting only the distinct ones).

The product of its digits is 720, while the sum is 21.

The square root of 645312 is about 803.3131394419. The cubic root of 645312 is about 86.4151550919.

Adding to 645312 its reverse (213546), we get a palindrome (858858).

The spelling of 645312 in words is "six hundred forty-five thousand, three hundred twelve".