645772252 has 24 divisors (see below), whose sum is σ = 1148348880. Its totient is φ = 317708160.

The previous prime is 645772241. The next prime is 645772271. The reversal of 645772252 is 252277546.

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 7 ways as a sum of consecutive naturals, for example, 70818 + ... + 79414.

It is an arithmetic number, because the mean of its divisors is an integer number (47847870).

Almost surely, 2^645772252 is an apocalyptic number.

It is an amenable number.

645772252 is a deficient number, since it is larger than the sum of its proper divisors (502576628).

645772252 is a wasteful number, since it uses less digits than its factorization.

645772252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8901 (or 8899 counting only the distinct ones).

The product of its digits is 235200, while the sum is 40.

The square root of 645772252 is about 25412.0493467174. The cubic root of 645772252 is about 864.3569466349.

The spelling of 645772252 in words is "six hundred forty-five million, seven hundred seventy-two thousand, two hundred fifty-two".