638634334605 has 32 divisors (see below), whose sum is σ = 1082761603200. Its totient is φ = 320320530432.

The previous prime is 638634334579. The next prime is 638634334607. The reversal of 638634334605 is 506433436836.

It is not a de Polignac number, because 638634334605 - 2⁵ = 638634334573 is a prime.

It is a super-2 number, since 2×638634334605² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638634334607) 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, 642775 + ... + 1300164.

It is an arithmetic number, because the mean of its divisors is an integer number (33836300100).

Almost surely, 2^638634334605 is an apocalyptic number.

It is an amenable number.

638634334605 is a deficient number, since it is larger than the sum of its proper divisors (444127268595).

638634334605 is a wasteful number, since it uses less digits than its factorization.

638634334605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1944253.

The product of its (nonzero) digits is 11197440, while the sum is 51.

The spelling of 638634334605 in words is "six hundred thirty-eight billion, six hundred thirty-four million, three hundred thirty-four thousand, six hundred five".