21100011100 has 72 divisors (see below), whose sum is σ = 55082168960. Its totient is φ = 6853533120.

The previous prime is 21100011071. The next prime is 21100011143. The reversal of 21100011100 is 111000112.

It is a Harshad number since it is a multiple of its sum of digits (7).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 779934 + ... + 806533.

Almost surely, 2^21100011100 is an apocalyptic number.

21100011100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100011100 is an abundant number, since it is smaller than the sum of its proper divisors (33982157860).

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

21100011100 is a wasteful number, since it uses less digits than its factorization.

21100011100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1586507 (or 1586500 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 7.

Adding to 21100011100 its reverse (111000112), we get a palindrome (21211011212).

The spelling of 21100011100 in words is "twenty-one billion, one hundred million, eleven thousand, one hundred".