21202111220 has 48 divisors (see below), whose sum is σ = 44990225280. Its totient is φ = 8392246656.

The previous prime is 21202111171. The next prime is 21202111253. The reversal of 21202111220 is 2211120212.

It is a junction number, because it is equal to n+sod(n) for n = 21202111195 and 21202111204.

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, 3567011 + ... + 3572949.

It is an arithmetic number, because the mean of its divisors is an integer number (937296360).

Almost surely, 2^21202111220 is an apocalyptic number.

21202111220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21202111220 is an abundant number, since it is smaller than the sum of its proper divisors (23788114060).

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

21202111220 is a wasteful number, since it uses less digits than its factorization.

21202111220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7784 (or 7782 counting only the distinct ones).

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

Adding to 21202111220 its reverse (2211120212), we get a palindrome (23413231432).

The spelling of 21202111220 in words is "twenty-one billion, two hundred two million, one hundred eleven thousand, two hundred twenty".