21001121002220 has 24 divisors (see below), whose sum is σ = 44163692596800. Its totient is φ = 8388764878592.

The previous prime is 21001121002153. The next prime is 21001121002223. The reversal of 21001121002220 is 2220012110012.

It is a junction number, because it is equal to n+sod(n) for n = 21001121002195 and 21001121002204.

It is not an unprimeable number, because it can be changed into a prime (21001121002223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 730205405 + ... + 730234164.

It is an arithmetic number, because the mean of its divisors is an integer number (1840153858200).

Almost surely, 2^{21001121002220} is an apocalyptic number.

21001121002220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001121002220 is an abundant number, since it is smaller than the sum of its proper divisors (23162571594580).

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

21001121002220 is a wasteful number, since it uses less digits than its factorization.

21001121002220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1460440297 (or 1460440295 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21001121002220 its reverse (2220012110012), we get a palindrome (23221133112232).

The spelling of 21001121002220 in words is "twenty-one trillion, one billion, one hundred twenty-one million, two thousand, two hundred twenty".