21101099988 has 24 divisors (see below), whose sum is σ = 49318113600. Its totient is φ = 7021955200.

The previous prime is 21101099983. The next prime is 21101099989. The reversal of 21101099988 is 88999010112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101099983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1460613 + ... + 1474988.

It is an arithmetic number, because the mean of its divisors is an integer number (2054921400).

Almost surely, 2^21101099988 is an apocalyptic number.

It is an amenable number.

21101099988 is an abundant number, since it is smaller than the sum of its proper divisors (28217013612).

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

21101099988 is a wasteful number, since it uses less digits than its factorization.

21101099988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2936207 (or 2936205 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 48.

The spelling of 21101099988 in words is "twenty-one billion, one hundred one million, ninety-nine thousand, nine hundred eighty-eight".