21120400016600 has 48 divisors (see below), whose sum is σ = 49351688574000. Its totient is φ = 8405706925440.

The previous prime is 21120400016591. The next prime is 21120400016621. The reversal of 21120400016600 is 661000402112.

It is a super-2 number, since 2×21120400016600² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 265291859 + ... + 265371458.

It is an arithmetic number, because the mean of its divisors is an integer number (1028160178625).

Almost surely, 2^{21120400016600} is an apocalyptic number.

21120400016600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21120400016600 is an abundant number, since it is smaller than the sum of its proper divisors (28231288557400).

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

21120400016600 is a wasteful number, since it uses less digits than its factorization.

21120400016600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530663532 (or 530663523 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

Adding to 21120400016600 its reverse (661000402112), we get a palindrome (21781400418712).

The spelling of 21120400016600 in words is "twenty-one trillion, one hundred twenty billion, four hundred million, sixteen thousand, six hundred".