21112002120 has 64 divisors (see below), whose sum is σ = 69093829440. Its totient is φ = 5118060800.

The previous prime is 21112002097. The next prime is 21112002173. The reversal of 21112002120 is 2120021112.

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

It is a junction number, because it is equal to n+sod(n) for n = 21112002096 and 21112002105.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7995651 + ... + 7998290.

It is an arithmetic number, because the mean of its divisors is an integer number (1079591085).

Almost surely, 2^21112002120 is an apocalyptic number.

21112002120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21112002120 is an abundant number, since it is smaller than the sum of its proper divisors (47981827320).

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

21112002120 is a wasteful number, since it uses less digits than its factorization.

21112002120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15993966 (or 15993962 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21112002120 its reverse (2120021112), we get a palindrome (23232023232).

The spelling of 21112002120 in words is "twenty-one billion, one hundred twelve million, two thousand, one hundred twenty".