21001200122120 has 64 divisors (see below), whose sum is σ = 48356846778240. Its totient is φ = 8204229734400.

The previous prime is 21001200122117. The next prime is 21001200122171. The reversal of 21001200122120 is 2122100210012.

It is a junction number, because it is equal to n+sod(n) for n = 21001200122095 and 21001200122104.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15305525 + ... + 16621115.

It is an arithmetic number, because the mean of its divisors is an integer number (755575730910).

Almost surely, 2^{21001200122120} is an apocalyptic number.

21001200122120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001200122120 is an abundant number, since it is smaller than the sum of its proper divisors (27355646656120).

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

21001200122120 is a wasteful number, since it uses less digits than its factorization.

21001200122120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1324926 (or 1324922 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21001200122120 its reverse (2122100210012), we get a palindrome (23123300332132).

The spelling of 21001200122120 in words is "twenty-one trillion, one billion, two hundred million, one hundred twenty-two thousand, one hundred twenty".