634400645 has 24 divisors (see below), whose sum is σ = 816371784. Its totient is φ = 471597056.

The previous prime is 634400639. The next prime is 634400659. The reversal of 634400645 is 546004436.

It can be written as a sum of positive squares in 12 ways, for example, as 217156 + 634183489 = 466^2 + 25183^2 .

It is not a de Polignac number, because 634400645 - 2⁶ = 634400581 is a prime.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2468357 + ... + 2468613.

It is an arithmetic number, because the mean of its divisors is an integer number (34015491).

Almost surely, 2^634400645 is an apocalyptic number.

It is an amenable number.

634400645 is a deficient number, since it is larger than the sum of its proper divisors (181971139).

634400645 is a wasteful number, since it uses less digits than its factorization.

634400645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649 (or 392 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 32.

The square root of 634400645 is about 25187.3111903593. The cubic root of 634400645 is about 859.2532931688.

The spelling of 634400645 in words is "six hundred thirty-four million, four hundred thousand, six hundred forty-five".