21101002100 has 36 divisors (see below), whose sum is σ = 45796548000. Its totient is φ = 8439041760.

The previous prime is 21101002099. The next prime is 21101002129. The reversal of 21101002100 is 120010112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 805001 + ... + 830799.

Almost surely, 2^21101002100 is an apocalyptic number.

21101002100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21101002100 is an abundant number, since it is smaller than the sum of its proper divisors (24695545900).

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

21101002100 is a wasteful number, since it uses less digits than its factorization.

21101002100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33992 (or 33985 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21101002100 its reverse (120010112), we get a palindrome (21221012212).

The spelling of 21101002100 in words is "twenty-one billion, one hundred one million, two thousand, one hundred".