21221221112120 has 64 divisors (see below), whose sum is σ = 48432924669600. Its totient is φ = 8367419660800.

The previous prime is 21221221112093. The next prime is 21221221112167. The reversal of 21221221112120 is 2121112212212.

It is a super-2 number, since 2×21221221112120² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21221221112092 and 21221221112101.

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, 10652915 + ... + 12487074.

Almost surely, 2^{21221221112120} is an apocalyptic number.

21221221112120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221221112120 is an abundant number, since it is smaller than the sum of its proper divisors (27211703557480).

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

21221221112120 is a wasteful number, since it uses less digits than its factorization.

21221221112120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23140328 (or 23140324 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 21221221112120 its reverse (2121112212212), we get a palindrome (23342333324332).

The spelling of 21221221112120 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twenty-one million, one hundred twelve thousand, one hundred twenty".