21102113220 has 24 divisors (see below), whose sum is σ = 59085917184. Its totient is φ = 5627230176.

The previous prime is 21102113173. The next prime is 21102113237. The reversal of 21102113220 is 2231120112.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21102113220.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175850884 + ... + 175851003.

It is an arithmetic number, because the mean of its divisors is an integer number (2461913216).

Almost surely, 2^21102113220 is an apocalyptic number.

21102113220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21102113220 is an abundant number, since it is smaller than the sum of its proper divisors (37983803964).

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

21102113220 is a wasteful number, since it uses less digits than its factorization.

21102113220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351701899 (or 351701897 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21102113220 its reverse (2231120112), we get a palindrome (23333233332).

The spelling of 21102113220 in words is "twenty-one billion, one hundred two million, one hundred thirteen thousand, two hundred twenty".