645640716 has 24 divisors (see below), whose sum is σ = 1721708800. Its totient is φ = 184468752.

The previous prime is 645640711. The next prime is 645640727. The reversal of 645640716 is 617046546.

645640716 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (645640711) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3843016 + ... + 3843183.

Almost surely, 2^645640716 is an apocalyptic number.

It is an amenable number.

645640716 is an abundant number, since it is smaller than the sum of its proper divisors (1076068084).

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

645640716 is a wasteful number, since it uses less digits than its factorization.

645640716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7686213 (or 7686211 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 39.

The square root of 645640716 is about 25409.4611513113. The cubic root of 645640716 is about 864.2982562967.

The spelling of 645640716 in words is "six hundred forty-five million, six hundred forty thousand, seven hundred sixteen".