21112101122220 has 72 divisors (see below), whose sum is σ = 64464146379360. Its totient is φ = 5592609561600.

The previous prime is 21112101122153. The next prime is 21112101122237. The reversal of 21112101122220 is 2222110121112.

21112101122220 is a `hidden beast` number, since 2 + 111 + 210 + 1 + 122 + 220 = 666.

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 = 21112101122193 and 21112101122202.

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, 388348485 + ... + 388402844.

It is an arithmetic number, because the mean of its divisors is an integer number (895335366380).

Almost surely, 2^{21112101122220} is an apocalyptic number.

21112101122220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21112101122220 is an abundant number, since it is smaller than the sum of its proper divisors (43352045257140).

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

21112101122220 is a wasteful number, since it uses less digits than its factorization.

21112101122220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 776751495 (or 776751490 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21112101122220 its reverse (2222110121112), we get a palindrome (23334211243332).

The spelling of 21112101122220 in words is "twenty-one trillion, one hundred twelve billion, one hundred one million, one hundred twenty-two thousand, two hundred twenty".