21221110320 has 80 divisors (see below), whose sum is σ = 65810594400. Its totient is φ = 5656799232.

The previous prime is 21221110307. The next prime is 21221110321. The reversal of 21221110320 is 2301112212.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×21221110320² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21221110320.

It is not an unprimeable number, because it can be changed into a prime (21221110321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 670206 + ... + 701154.

It is an arithmetic number, because the mean of its divisors is an integer number (822632430).

Almost surely, 2^21221110320 is an apocalyptic number.

21221110320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221110320 is an abundant number, since it is smaller than the sum of its proper divisors (44589484080).

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

21221110320 is a wasteful number, since it uses less digits than its factorization.

21221110320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33822 (or 33816 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21221110320 its reverse (2301112212), we get a palindrome (23522222532).

The spelling of 21221110320 in words is "twenty-one billion, two hundred twenty-one million, one hundred ten thousand, three hundred twenty".