21100122120 has 128 divisors (see below), whose sum is σ = 78919971840. Its totient is φ = 4384439040.

The previous prime is 21100122107. The next prime is 21100122133. The reversal of 21100122120 is 2122100112.

It is an interprime number because it is at equal distance from previous prime (21100122107) and next prime (21100122133).

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 = 21100122096 and 21100122105.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1132542 + ... + 1151021.

It is an arithmetic number, because the mean of its divisors is an integer number (616562280).

Almost surely, 2^21100122120 is an apocalyptic number.

21100122120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100122120 is an abundant number, since it is smaller than the sum of its proper divisors (57819849720).

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

21100122120 is a wasteful number, since it uses less digits than its factorization.

21100122120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2283595 (or 2283591 counting only the distinct ones).

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

Adding to 21100122120 its reverse (2122100112), we get a palindrome (23222222232).

The spelling of 21100122120 in words is "twenty-one billion, one hundred million, one hundred twenty-two thousand, one hundred twenty".