645706252 has 6 divisors (see below), whose sum is σ = 1129985948. Its totient is φ = 322853124.

The previous prime is 645706213. The next prime is 645706283. The reversal of 645706252 is 252607546.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80713278 + ... + 80713285.

Almost surely, 2^645706252 is an apocalyptic number.

It is an amenable number.

645706252 is a deficient number, since it is larger than the sum of its proper divisors (484279696).

645706252 is a wasteful number, since it uses less digits than its factorization.

645706252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161426567 (or 161426565 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 37.

The square root of 645706252 is about 25410.7507169702. The cubic root of 645706252 is about 864.3274989455.

The spelling of 645706252 in words is "six hundred forty-five million, seven hundred six thousand, two hundred fifty-two".