21231111112220 has 24 divisors (see below), whose sum is σ = 44592512043408. Its totient is φ = 8491077072000.

The previous prime is 21231111112181. The next prime is 21231111112223. The reversal of 21231111112220 is 2221111113212.

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 = 21231111112192 and 21231111112201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231111112223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85333481 + ... + 85581920.

It is an arithmetic number, because the mean of its divisors is an integer number (1858021335142).

Almost surely, 2^{21231111112220} is an apocalyptic number.

21231111112220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21231111112220 is an abundant number, since it is smaller than the sum of its proper divisors (23361400931188).

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

21231111112220 is a wasteful number, since it uses less digits than its factorization.

21231111112220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170921621 (or 170921619 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 20.

Adding to 21231111112220 its reverse (2221111113212), we get a palindrome (23452222225432).

The spelling of 21231111112220 in words is "twenty-one trillion, two hundred thirty-one billion, one hundred eleven million, one hundred twelve thousand, two hundred twenty".