21321031110 has 32 divisors (see below), whose sum is σ = 51639936480. Its totient is φ = 5633445888.

The previous prime is 21321031063. The next prime is 21321031139. The reversal of 21321031110 is 1113012312.

It is a happy number.

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 21321031110.

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, 3256827 + ... + 3263366.

It is an arithmetic number, because the mean of its divisors is an integer number (1613748015).

Almost surely, 2^21321031110 is an apocalyptic number.

21321031110 is an abundant number, since it is smaller than the sum of its proper divisors (30318905370).

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

21321031110 is a wasteful number, since it uses less digits than its factorization.

21321031110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6520312.

The product of its (nonzero) digits is 36, while the sum is 15.

Adding to 21321031110 its reverse (1113012312), we get a palindrome (22434043422).

The spelling of 21321031110 in words is "twenty-one billion, three hundred twenty-one million, thirty-one thousand, one hundred ten".