102638888891 has 32 divisors (see below), whose sum is σ = 128911097856. Its totient is φ = 79388100000.

The previous prime is 102638888879. The next prime is 102638888959. The reversal of 102638888891 is 198888836201.

It is not a de Polignac number, because 102638888891 - 2⁶ = 102638888827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (102638888291) 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, 20728466 + ... + 20733416.

It is an arithmetic number, because the mean of its divisors is an integer number (4028471808).

Almost surely, 2^102638888891 is an apocalyptic number.

102638888891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

102638888891 is a deficient number, since it is larger than the sum of its proper divisors (26272208965).

102638888891 is a wasteful number, since it uses less digits than its factorization.

102638888891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6903.

The product of its (nonzero) digits is 10616832, while the sum is 62.

The spelling of 102638888891 in words is "one hundred two billion, six hundred thirty-eight million, eight hundred eighty-eight thousand, eight hundred ninety-one".