638655122644 has 96 divisors (see below), whose sum is σ = 1504152115200. Its totient is φ = 229800869760.

The previous prime is 638655122641. The next prime is 638655122663. The reversal of 638655122644 is 446221556836.

It is a junction number, because it is equal to n+sod(n) for n = 638655122591 and 638655122600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638655122641) 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, 1348954 + ... + 1759825.

It is an arithmetic number, because the mean of its divisors is an integer number (15668251200).

Almost surely, 2^638655122644 is an apocalyptic number.

It is an amenable number.

638655122644 is an abundant number, since it is smaller than the sum of its proper divisors (865496992556).

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

638655122644 is a wasteful number, since it uses less digits than its factorization.

638655122644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3108853 (or 3108851 counting only the distinct ones).

The product of its digits is 8294400, while the sum is 52.

The spelling of 638655122644 in words is "six hundred thirty-eight billion, six hundred fifty-five million, one hundred twenty-two thousand, six hundred forty-four".