645642605616 has 20 divisors (see below), whose sum is σ = 1667910064632. Its totient is φ = 215214201856.

The previous prime is 645642605599. The next prime is 645642605693. The reversal of 645642605616 is 616506246546.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6725443761 + ... + 6725443856.

Almost surely, 2^645642605616 is an apocalyptic number.

It is an amenable number.

645642605616 is an abundant number, since it is smaller than the sum of its proper divisors (1022267459016).

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

645642605616 is a wasteful number, since it uses less digits than its factorization.

645642605616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13450887628 (or 13450887622 counting only the distinct ones).

The product of its (nonzero) digits is 6220800, while the sum is 51.

The spelling of 645642605616 in words is "six hundred forty-five billion, six hundred forty-two million, six hundred five thousand, six hundred sixteen".