21112211212220 has 36 divisors (see below), whose sum is σ = 45917176645704. Its totient is φ = 8153681565120.

The previous prime is 21112211212187. The next prime is 21112211212231. The reversal of 21112211212220 is 2221211221112.

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 = 21112211212192 and 21112211212201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 627575666 + ... + 627609305.

Almost surely, 2^{21112211212220} is an apocalyptic number.

21112211212220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21112211212220 is an abundant number, since it is smaller than the sum of its proper divisors (24804965433484).

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

21112211212220 is a wasteful number, since it uses less digits than its factorization.

21112211212220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1255185038 (or 1255185007 counting only the distinct ones).

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

Adding to 21112211212220 its reverse (2221211221112), we get a palindrome (23333422433332).

The spelling of 21112211212220 in words is "twenty-one trillion, one hundred twelve billion, two hundred eleven million, two hundred twelve thousand, two hundred twenty".