645272 has 16 divisors (see below), whose sum is σ = 1226400. Its totient is φ = 318240.

The previous prime is 645257. The next prime is 645313. The reversal of 645272 is 272546.

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122 + ... + 1142.

It is an arithmetic number, because the mean of its divisors is an integer number (76650).

2⁶⁴⁵²⁷² is an apocalyptic number.

It is an amenable number.

645272 is a deficient number, since it is larger than the sum of its proper divisors (581128).

645272 is a wasteful number, since it uses less digits than its factorization.

645272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1106 (or 1102 counting only the distinct ones).

The product of its digits is 3360, while the sum is 26.

The square root of 645272 is about 803.2882421647. The cubic root of 645272 is about 86.4133695589.

The spelling of 645272 in words is "six hundred forty-five thousand, two hundred seventy-two".