645991833705 has 32 divisors (see below), whose sum is σ = 1088473680000. Its totient is φ = 326249644032.

The previous prime is 645991833679. The next prime is 645991833793. The reversal of 645991833705 is 507338199546.

It is not a de Polignac number, because 645991833705 - 2⁷ = 645991833577 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 130921 + ... + 1144169.

It is an arithmetic number, because the mean of its divisors is an integer number (34014802500).

Almost surely, 2^645991833705 is an apocalyptic number.

It is an amenable number.

645991833705 is a deficient number, since it is larger than the sum of its proper divisors (442481846295).

645991833705 is a wasteful number, since it uses less digits than its factorization.

645991833705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1015513.

The product of its (nonzero) digits is 24494400, while the sum is 60.

The spelling of 645991833705 in words is "six hundred forty-five billion, nine hundred ninety-one million, eight hundred thirty-three thousand, seven hundred five".