21112112221220 has 24 divisors (see below), whose sum is σ = 44600917322304. Its totient is φ = 8394276953696.

The previous prime is 21112112221199. The next prime is 21112112221259. The reversal of 21112112221220 is 2212221121112.

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 = 21112112221192 and 21112112221201.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3160492502 + ... + 3160499181.

It is an arithmetic number, because the mean of its divisors is an integer number (1858371555096).

Almost surely, 2^{21112112221220} is an apocalyptic number.

21112112221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21112112221220 is an abundant number, since it is smaller than the sum of its proper divisors (23488805101084).

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

21112112221220 is a wasteful number, since it uses less digits than its factorization.

21112112221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6320991859 (or 6320991857 counting only the distinct ones).

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

Adding to 21112112221220 its reverse (2212221121112), we get a palindrome (23324333342332).

The spelling of 21112112221220 in words is "twenty-one trillion, one hundred twelve billion, one hundred twelve million, two hundred twenty-one thousand, two hundred twenty".