638633412 has 36 divisors (see below), whose sum is σ = 1615741036. Its totient is φ = 212690880.

The previous prime is 638633381. The next prime is 638633467. The reversal of 638633412 is 214336836.

638633412 is a `hidden beast` number, since 6 + 3 + 8 + 633 + 4 + 12 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 198640836 + 439992576 = 14094^2 + 20976^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37362 + ... + 51702.

Almost surely, 2^638633412 is an apocalyptic number.

It is an amenable number.

638633412 is an abundant number, since it is smaller than the sum of its proper divisors (977107624).

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

638633412 is a wasteful number, since it uses less digits than its factorization.

638633412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15588 (or 15583 counting only the distinct ones).

The product of its digits is 62208, while the sum is 36.

The square root of 638633412 is about 25271.1972806988. The cubic root of 638633412 is about 861.1600587881.

The spelling of 638633412 in words is "six hundred thirty-eight million, six hundred thirty-three thousand, four hundred twelve".