21021210011220 has 24 divisors (see below), whose sum is σ = 58859388031584. Its totient is φ = 5605656002976.

The previous prime is 21021210011213. The next prime is 21021210011233. The reversal of 21021210011220 is 2211001212012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21021210011220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175176750034 + ... + 175176750153.

It is an arithmetic number, because the mean of its divisors is an integer number (2452474501316).

Almost surely, 2^{21021210011220} is an apocalyptic number.

21021210011220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021210011220 is an abundant number, since it is smaller than the sum of its proper divisors (37838178020364).

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

21021210011220 is a wasteful number, since it uses less digits than its factorization.

21021210011220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350353500199 (or 350353500197 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21021210011220 its reverse (2211001212012), we get a palindrome (23232211223232).

The spelling of 21021210011220 in words is "twenty-one trillion, twenty-one billion, two hundred ten million, eleven thousand, two hundred twenty".