21103031100 has 36 divisors (see below), whose sum is σ = 61058104184. Its totient is φ = 5627474880.

The previous prime is 21103031029. The next prime is 21103031119. The reversal of 21103031100 is 113030112.

It is a Harshad number since it is a multiple of its sum of digits (12).

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, 35171419 + ... + 35172018.

Almost surely, 2^21103031100 is an apocalyptic number.

21103031100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21103031100 is an abundant number, since it is smaller than the sum of its proper divisors (39955073084).

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

21103031100 is a wasteful number, since it uses less digits than its factorization.

21103031100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70343454 (or 70343447 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 12.

Adding to 21103031100 its reverse (113030112), we get a palindrome (21216061212).

The spelling of 21103031100 in words is "twenty-one billion, one hundred three million, thirty-one thousand, one hundred".