21121200111220 has 72 divisors (see below), whose sum is σ = 48803222131272. Its totient is φ = 7672574300160.

The previous prime is 21121200111161. The next prime is 21121200111239. The reversal of 21121200111220 is 2211100212112.

It can be written as a sum of positive squares in 4 ways, for example, as 2568435737956 + 18552764373264 = 1602634^2 + 4307292^2 .

It is a super-2 number, since 2×21121200111220² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21121200111194 and 21121200111203.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2102277 + ... + 6830956.

It is an arithmetic number, because the mean of its divisors is an integer number (677822529601).

Almost surely, 2^{21121200111220} is an apocalyptic number.

21121200111220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121200111220 is an abundant number, since it is smaller than the sum of its proper divisors (27682022020052).

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

21121200111220 is a wasteful number, since it uses less digits than its factorization.

21121200111220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8934241 (or 8934228 counting only the distinct ones).

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

Adding to 21121200111220 its reverse (2211100212112), we get a palindrome (23332300323332).

The spelling of 21121200111220 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred million, one hundred eleven thousand, two hundred twenty".