645752179 has 4 divisors (see below), whose sum is σ = 645970360. Its totient is φ = 645534000.

The previous prime is 645752137. The next prime is 645752197. The reversal of 645752179 is 971257546.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645752179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645752879) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104589 + ... + 110590.

It is an arithmetic number, because the mean of its divisors is an integer number (161492590).

Almost surely, 2^645752179 is an apocalyptic number.

645752179 is a deficient number, since it is larger than the sum of its proper divisors (218181).

645752179 is a wasteful number, since it uses less digits than its factorization.

645752179 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218180.

The product of its digits is 529200, while the sum is 46.

The square root of 645752179 is about 25411.6543932110. The cubic root of 645752179 is about 864.3479907340.

The spelling of 645752179 in words is "six hundred forty-five million, seven hundred fifty-two thousand, one hundred seventy-nine".