645700716 has 18 divisors (see below), whose sum is σ = 1632188012. Its totient is φ = 215233560.

The previous prime is 645700709. The next prime is 645700729. The reversal of 645700716 is 617007546.

645700716 is a `hidden beast` number, since 645 + 7 + 0 + 0 + 7 + 1 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 17936131 = 645700716 / (6 + 4 + 5 + 7 + 0 + 0 + 7 + 1 + 6).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8968030 + ... + 8968101.

Almost surely, 2^645700716 is an apocalyptic number.

It is an amenable number.

645700716 is an abundant number, since it is smaller than the sum of its proper divisors (986487296).

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

645700716 is a wasteful number, since it uses less digits than its factorization.

645700716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17936141 (or 17936136 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 36.

The square root of 645700716 is about 25410.6417864642. The cubic root of 645700716 is about 864.3250288178.

It can be divided in two parts, 645700 and 716, that added together give a square (646416 = 804²).

The spelling of 645700716 in words is "six hundred forty-five million, seven hundred thousand, seven hundred sixteen".