21121202120220 has 72 divisors (see below), whose sum is σ = 64164866285520. Its totient is φ = 5623773765120.

The previous prime is 21121202120153. The next prime is 21121202120237. The reversal of 21121202120220 is 2202120212112.

It is a happy number.

21121202120220 is a `hidden beast` number, since 2 + 1 + 121 + 202 + 120 + 220 = 666.

It is a super-2 number, since 2×21121202120220² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21121202120193 and 21121202120202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 88910221 + ... + 89147460.

It is an arithmetic number, because the mean of its divisors is an integer number (891178698410).

Almost surely, 2^{21121202120220} is an apocalyptic number.

21121202120220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121202120220 is an abundant number, since it is smaller than the sum of its proper divisors (43043664165300).

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

21121202120220 is a wasteful number, since it uses less digits than its factorization.

21121202120220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178058355 (or 178058350 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21121202120220 its reverse (2202120212112), we get a palindrome (23323322332332).

The spelling of 21121202120220 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred two million, one hundred twenty thousand, two hundred twenty".