21012210111220 has 48 divisors (see below), whose sum is σ = 44685037877760. Its totient is φ = 8298336324096.

The previous prime is 21012210111187. The next prime is 21012210111223. The reversal of 21012210111220 is 2211101221012.

It is a junction number, because it is equal to n+sod(n) for n = 21012210111194 and 21012210111203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012210111223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 119665209 + ... + 119840671.

It is an arithmetic number, because the mean of its divisors is an integer number (930938289120).

Almost surely, 2^{21012210111220} is an apocalyptic number.

21012210111220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012210111220 is an abundant number, since it is smaller than the sum of its proper divisors (23672827766540).

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

21012210111220 is a wasteful number, since it uses less digits than its factorization.

21012210111220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251344 (or 251342 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21012210111220 its reverse (2211101221012), we get a palindrome (23223311332232).

The spelling of 21012210111220 in words is "twenty-one trillion, twelve billion, two hundred ten million, one hundred eleven thousand, two hundred twenty".