645516813291 has 32 divisors (see below), whose sum is σ = 993895795200. Its totient is φ = 365030945280.

The previous prime is 645516813247. The next prime is 645516813353. The reversal of 645516813291 is 192318615546.

It is not a de Polignac number, because 645516813291 - 2⁹ = 645516812779 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645516813691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1682515 + ... + 2030243.

It is an arithmetic number, because the mean of its divisors is an integer number (31059243600).

Almost surely, 2^645516813291 is an apocalyptic number.

645516813291 is a deficient number, since it is larger than the sum of its proper divisors (348378981909).

645516813291 is a wasteful number, since it uses less digits than its factorization.

645516813291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 348659.

The product of its digits is 1555200, while the sum is 51.

The spelling of 645516813291 in words is "six hundred forty-five billion, five hundred sixteen million, eight hundred thirteen thousand, two hundred ninety-one".