21000122212220 has 48 divisors (see below), whose sum is σ = 44131257535680. Its totient is φ = 8394145990656.

The previous prime is 21000122212211. The next prime is 21000122212247. The reversal of 21000122212220 is 2221222100012.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 173046284 + ... + 173167596.

It is an arithmetic number, because the mean of its divisors is an integer number (919401198660).

Almost surely, 2^{21000122212220} is an apocalyptic number.

21000122212220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000122212220 is an abundant number, since it is smaller than the sum of its proper divisors (23131135323460).

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

21000122212220 is a wasteful number, since it uses less digits than its factorization.

21000122212220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127334 (or 127332 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21000122212220 its reverse (2221222100012), we get a palindrome (23221344312232).

The spelling of 21000122212220 in words is "twenty-one trillion, one hundred twenty-two million, two hundred twelve thousand, two hundred twenty".