21231322220 has 48 divisors (see below), whose sum is σ = 45695881728. Its totient is φ = 8282362560.

The previous prime is 21231322213. The next prime is 21231322291. The reversal of 21231322220 is 2222313212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21231322192 and 21231322201.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 226115 + ... + 305925.

It is an arithmetic number, because the mean of its divisors is an integer number (951997536).

Almost surely, 2^21231322220 is an apocalyptic number.

21231322220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21231322220 is an abundant number, since it is smaller than the sum of its proper divisors (24464559508).

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

21231322220 is a wasteful number, since it uses less digits than its factorization.

21231322220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80150 (or 80148 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21231322220 its reverse (2222313212), we get a palindrome (23453635432).

The spelling of 21231322220 in words is "twenty-one billion, two hundred thirty-one million, three hundred twenty-two thousand, two hundred twenty".