645875522 has 4 divisors (see below), whose sum is σ = 968813286. Its totient is φ = 322937760.

The previous prime is 645875521. The next prime is 645875533. The reversal of 645875522 is 225578546.

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

It can be written as a sum of positive squares in only one way, i.e., 357928561 + 287946961 = 18919^2 + 16969^2 .

It is not an unprimeable number, because it can be changed into a prime (645875521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161468879 + ... + 161468882.

Almost surely, 2^645875522 is an apocalyptic number.

645875522 is a deficient number, since it is larger than the sum of its proper divisors (322937764).

645875522 is a wasteful number, since it uses less digits than its factorization.

645875522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322937763.

The product of its digits is 672000, while the sum is 44.

The square root of 645875522 is about 25414.0811756003. The cubic root of 645875522 is about 864.4030193196.

The spelling of 645875522 in words is "six hundred forty-five million, eight hundred seventy-five thousand, five hundred twenty-two".