645122757 has 8 divisors (see below), whose sum is σ = 860292576. Its totient is φ = 430017392.

The previous prime is 645122747. The next prime is 645122759. The reversal of 645122757 is 757221546.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 645122757 - 2⁶ = 645122693 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645122759) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16918 + ... + 39704.

It is an arithmetic number, because the mean of its divisors is an integer number (107536572).

Almost surely, 2^645122757 is an apocalyptic number.

It is an amenable number.

645122757 is a deficient number, since it is larger than the sum of its proper divisors (215169819).

645122757 is a wasteful number, since it uses less digits than its factorization.

645122757 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32227.

The product of its digits is 117600, while the sum is 39.

The square root of 645122757 is about 25399.2668594981. The cubic root of 645122757 is about 864.0670694998.

The spelling of 645122757 in words is "six hundred forty-five million, one hundred twenty-two thousand, seven hundred fifty-seven".