638407403085 has 32 divisors (see below), whose sum is σ = 1029150904320. Its totient is φ = 337919266368.

The previous prime is 638407403083. The next prime is 638407403209. The reversal of 638407403085 is 580304704836.

It is not a de Polignac number, because 638407403085 - 2¹ = 638407403083 is a prime.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638407403083) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6252312 + ... + 6353598.

It is an arithmetic number, because the mean of its divisors is an integer number (32160965760).

Almost surely, 2^638407403085 is an apocalyptic number.

It is an amenable number.

638407403085 is a deficient number, since it is larger than the sum of its proper divisors (390743501235).

638407403085 is a wasteful number, since it uses less digits than its factorization.

638407403085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104457.

The product of its (nonzero) digits is 1935360, while the sum is 48.

The spelling of 638407403085 in words is "six hundred thirty-eight billion, four hundred seven million, four hundred three thousand, eighty-five".