638636213622 has 32 divisors (see below), whose sum is σ = 1431047245824. Its totient is φ = 188295688800.

The previous prime is 638636213617. The next prime is 638636213647. The reversal of 638636213622 is 226312636836.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 130758454 + ... + 130763337.

It is an arithmetic number, because the mean of its divisors is an integer number (44720226432).

Almost surely, 2^638636213622 is an apocalyptic number.

638636213622 is an abundant number, since it is smaller than the sum of its proper divisors (792411032202).

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

638636213622 is a wasteful number, since it uses less digits than its factorization.

638636213622 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261521844.

The product of its digits is 2239488, while the sum is 48.

It can be divided in two parts, 638636 and 213622, that added together give a palindrome (852258).

The spelling of 638636213622 in words is "six hundred thirty-eight billion, six hundred thirty-six million, two hundred thirteen thousand, six hundred twenty-two".