21221122111220 has 48 divisors (see below), whose sum is σ = 47850377799168. Its totient is φ = 7876605381120.

The previous prime is 21221122111201. The next prime is 21221122111303. The reversal of 21221122111220 is 2211122112212.

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 = 21221122111192 and 21221122111201.

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, 439518572 + ... + 439566851.

It is an arithmetic number, because the mean of its divisors is an integer number (996882870816).

Almost surely, 2^{21221122111220} is an apocalyptic number.

21221122111220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221122111220 is an abundant number, since it is smaller than the sum of its proper divisors (26629255687948).

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

21221122111220 is a wasteful number, since it uses less digits than its factorization.

21221122111220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 879085520 (or 879085518 counting only the distinct ones).

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

Adding to 21221122111220 its reverse (2211122112212), we get a palindrome (23432244223432).

The spelling of 21221122111220 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred twenty-two million, one hundred eleven thousand, two hundred twenty".