645900272 has 20 divisors (see below), whose sum is σ = 1253099856. Its totient is φ = 322519680.

The previous prime is 645900263. The next prime is 645900361. The reversal of 645900272 is 272009546.

It is a super-2 number, since 2×645900272² = 834374322739347968, which contains 22 as substring.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14348 + ... + 38699.

Almost surely, 2^645900272 is an apocalyptic number.

It is an amenable number.

645900272 is a deficient number, since it is larger than the sum of its proper divisors (607199584).

645900272 is a wasteful number, since it uses less digits than its factorization.

645900272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53816 (or 53810 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 645900272 is about 25414.5681057145. The cubic root of 645900272 is about 864.4140605088.

The spelling of 645900272 in words is "six hundred forty-five million, nine hundred thousand, two hundred seventy-two".