21110111220120 has 128 divisors (see below), whose sum is σ = 68384746584000. Its totient is φ = 5182403733504.

The previous prime is 21110111220109. The next prime is 21110111220137. The reversal of 21110111220120 is 2102211101112.

It is a happy number.

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 21110111220120.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17557695 + ... + 18721454.

Almost surely, 2^{21110111220120} is an apocalyptic number.

21110111220120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21110111220120 is an abundant number, since it is smaller than the sum of its proper divisors (47274635363880).

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

21110111220120 is a wasteful number, since it uses less digits than its factorization.

21110111220120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36279549 (or 36279545 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21110111220120 its reverse (2102211101112), we get a palindrome (23212322321232).

The spelling of 21110111220120 in words is "twenty-one trillion, one hundred ten billion, one hundred eleven million, two hundred twenty thousand, one hundred twenty".