634821128 has 8 divisors (see below), whose sum is σ = 1190289630. Its totient is φ = 317410560.

The previous prime is 634821127. The next prime is 634821149. The reversal of 634821128 is 821128436.

It can be written as a sum of positive squares in only one way, i.e., 574944484 + 59876644 = 23978^2 + 7738^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (634821127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39676313 + ... + 39676328.

Almost surely, 2^634821128 is an apocalyptic number.

It is an amenable number.

634821128 is a deficient number, since it is larger than the sum of its proper divisors (555468502).

634821128 is a wasteful number, since it uses less digits than its factorization.

634821128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79352647 (or 79352643 counting only the distinct ones).

The product of its digits is 18432, while the sum is 35.

The square root of 634821128 is about 25195.6569273357. The cubic root of 634821128 is about 859.4430899535.

The spelling of 634821128 in words is "six hundred thirty-four million, eight hundred twenty-one thousand, one hundred twenty-eight".