634440564 has 18 divisors (see below), whose sum is σ = 1603724850. Its totient is φ = 211480176.

The previous prime is 634440559. The next prime is 634440577. The reversal of 634440564 is 465044436.

634440564 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 436475664 + 197964900 = 20892^2 + 14070^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 17623349 = 634440564 / (6 + 3 + 4 + 4 + 4 + 0 + 5 + 6 + 4).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8811639 + ... + 8811710.

It is an arithmetic number, because the mean of its divisors is an integer number (89095825).

Almost surely, 2^634440564 is an apocalyptic number.

It is an amenable number.

634440564 is an abundant number, since it is smaller than the sum of its proper divisors (969284286).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

634440564 is a wasteful number, since it uses less digits than its factorization.

634440564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17623359 (or 17623354 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 36.

The square root of 634440564 is about 25188.1036205587. The cubic root of 634440564 is about 859.2713153304.

The spelling of 634440564 in words is "six hundred thirty-four million, four hundred forty thousand, five hundred sixty-four".