645315634 has 4 divisors (see below), whose sum is σ = 967973454. Its totient is φ = 322657816.

The previous prime is 645315617. The next prime is 645315647. The reversal of 645315634 is 436513546.

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., 645007609 + 308025 = 25397^2 + 555^2 .

It is a junction number, because it is equal to n+sod(n) for n = 645315593 and 645315602.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161328907 + ... + 161328910.

Almost surely, 2^645315634 is an apocalyptic number.

645315634 is a deficient number, since it is larger than the sum of its proper divisors (322657820).

645315634 is a wasteful number, since it uses less digits than its factorization.

645315634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322657819.

The product of its digits is 129600, while the sum is 37.

The square root of 645315634 is about 25403.0634766754. The cubic root of 645315634 is about 864.1531730391.

The spelling of 645315634 in words is "six hundred forty-five million, three hundred fifteen thousand, six hundred thirty-four".