638101836 has 36 divisors (see below), whose sum is σ = 1637060152. Its totient is φ = 209525184.

The previous prime is 638101831. The next prime is 638101843.

638101836 is a `hidden beast` number, since 638 + 1 + 0 + 18 + 3 + 6 = 666.

638101836 is nontrivially palindromic in base 10.

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

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

It is an alternating number because its digits alternate between even and odd.

It is a self number, because there is not a number n which added to its sum of digits gives 638101836.

It is not an unprimeable number, because it can be changed into a prime (638101831) by changing a digit.

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, 129865 + ... + 134688.

Almost surely, 2^638101836 is an apocalyptic number.

It is an amenable number.

638101836 is an abundant number, since it is smaller than the sum of its proper divisors (998958316).

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

638101836 is a wasteful number, since it uses less digits than its factorization.

638101836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264630 (or 264625 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 638101836 is about 25260.6776631190. The cubic root of 638101836 is about 860.9210593451.

The spelling of 638101836 in words is "six hundred thirty-eight million, one hundred one thousand, eight hundred thirty-six".