21222201220 has 24 divisors (see below), whose sum is σ = 48618134208. Its totient is φ = 7717164000.

The previous prime is 21222201199. The next prime is 21222201233. The reversal of 21222201220 is 2210222212.

It is a junction number, because it is equal to n+sod(n) for n = 21222201194 and 21222201203.

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, 48232056 + ... + 48232495.

It is an arithmetic number, because the mean of its divisors is an integer number (2025755592).

Almost surely, 2^21222201220 is an apocalyptic number.

21222201220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21222201220 is an abundant number, since it is smaller than the sum of its proper divisors (27395932988).

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

21222201220 is a wasteful number, since it uses less digits than its factorization.

21222201220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96464571 (or 96464569 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21222201220 its reverse (2210222212), we get a palindrome (23432423432).

The spelling of 21222201220 in words is "twenty-one billion, two hundred twenty-two million, two hundred one thousand, two hundred twenty".