21202201220 has 24 divisors (see below), whose sum is σ = 45024903000. Its totient is φ = 8385588992.

The previous prime is 21202201201. The next prime is 21202201247. The reversal of 21202201220 is 2210220212.

It can be written as a sum of positive squares in 4 ways, for example, as 532963396 + 20669237824 = 23086^2 + 143768^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21202201195 and 21202201204.

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, 5953895 + ... + 5957454.

It is an arithmetic number, because the mean of its divisors is an integer number (1876037625).

Almost surely, 2^21202201220 is an apocalyptic number.

21202201220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21202201220 is an abundant number, since it is smaller than the sum of its proper divisors (23822701780).

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

21202201220 is a wasteful number, since it uses less digits than its factorization.

21202201220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11911447 (or 11911445 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21202201220 its reverse (2210220212), we get a palindrome (23412421432).

The spelling of 21202201220 in words is "twenty-one billion, two hundred two million, two hundred one thousand, two hundred twenty".