21101121100 has 18 divisors (see below), whose sum is σ = 45789433004. Its totient is φ = 8440448400.

The previous prime is 21101121071. The next prime is 21101121179. The reversal of 21101121100 is 112110112.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 105505506 + ... + 105505705.

Almost surely, 2^21101121100 is an apocalyptic number.

21101121100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21101121100 is an abundant number, since it is smaller than the sum of its proper divisors (24688311904).

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

21101121100 is a wasteful number, since it uses less digits than its factorization.

21101121100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211011225 (or 211011218 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21101121100 its reverse (112110112), we get a palindrome (21213231212).

The spelling of 21101121100 in words is "twenty-one billion, one hundred one million, one hundred twenty-one thousand, one hundred".