21221330220 has 72 divisors (see below), whose sum is σ = 65941424640. Its totient is φ = 5520994560.

The previous prime is 21221330219. The next prime is 21221330293. The reversal of 21221330220 is 2203312212.

It is a super-3 number, since 3×21221330220³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21221330193 and 21221330202.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1430380 + ... + 1445139.

It is an arithmetic number, because the mean of its divisors is an integer number (915853120).

Almost surely, 2^21221330220 is an apocalyptic number.

21221330220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221330220 is an abundant number, since it is smaller than the sum of its proper divisors (44720094420).

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

21221330220 is a wasteful number, since it uses less digits than its factorization.

21221330220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2875575 (or 2875570 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21221330220 its reverse (2203312212), we get a palindrome (23424642432).

The spelling of 21221330220 in words is "twenty-one billion, two hundred twenty-one million, three hundred thirty thousand, two hundred twenty".