645915699 has 48 divisors (see below), whose sum is σ = 1103182080. Its totient is φ = 359017920.

The previous prime is 645915691. The next prime is 645915703. The reversal of 645915699 is 996519546.

It is not a de Polignac number, because 645915699 - 2³ = 645915691 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645915691) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 208242 + ... + 211320.

It is an arithmetic number, because the mean of its divisors is an integer number (22982960).

Almost surely, 2^645915699 is an apocalyptic number.

645915699 is a deficient number, since it is larger than the sum of its proper divisors (457266381).

645915699 is a wasteful number, since it uses less digits than its factorization.

645915699 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3272 (or 3269 counting only the distinct ones).

The product of its digits is 2624400, while the sum is 54.

The square root of 645915699 is about 25414.8716109289. The cubic root of 645915699 is about 864.4209424843.

The spelling of 645915699 in words is "six hundred forty-five million, nine hundred fifteen thousand, six hundred ninety-nine".