21111552120 has 64 divisors (see below), whose sum is σ = 64682219520. Its totient is φ = 5509963904.

The previous prime is 21111552107. The next prime is 21111552151. The reversal of 21111552120 is 2125511112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1865952 + ... + 1877231.

It is an arithmetic number, because the mean of its divisors is an integer number (1010659680).

Almost surely, 2^21111552120 is an apocalyptic number.

21111552120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21111552120 is an abundant number, since it is smaller than the sum of its proper divisors (43570667400).

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

21111552120 is a wasteful number, since it uses less digits than its factorization.

21111552120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3743244 (or 3743240 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 21.

The spelling of 21111552120 in words is "twenty-one billion, one hundred eleven million, five hundred fifty-two thousand, one hundred twenty".