638620638923168 has 24 divisors (see below), whose sum is σ = 1371582963142560. Its totient is φ = 290282108601280.

The previous prime is 638620638923161. The next prime is 638620638923257. The reversal of 638620638923168 is 861329836026836.

It is not an unprimeable number, because it can be changed into a prime (638620638923161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 907131589028 + ... + 907131589731.

It is an arithmetic number, because the mean of its divisors is an integer number (57149290130940).

Almost surely, 2^{638620638923168} is an apocalyptic number.

It is an amenable number.

638620638923168 is an abundant number, since it is smaller than the sum of its proper divisors (732962324219392).

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

638620638923168 is a wasteful number, since it uses less digits than its factorization.

638620638923168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1814263178780 (or 1814263178772 counting only the distinct ones).

The product of its (nonzero) digits is 644972544, while the sum is 71.

The spelling of 638620638923168 in words is "six hundred thirty-eight trillion, six hundred twenty billion, six hundred thirty-eight million, nine hundred twenty-three thousand, one hundred sixty-eight".