21311113110 has 128 divisors (see below), whose sum is σ = 61018665984. Its totient is φ = 4661660160.

The previous prime is 21311113093. The next prime is 21311113157. The reversal of 21311113110 is 1131111312.

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 21311113110.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 451489 + ... + 496451.

It is an arithmetic number, because the mean of its divisors is an integer number (476708328).

Almost surely, 2^21311113110 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21311113110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30509332992).

21311113110 is an abundant number, since it is smaller than the sum of its proper divisors (39707552874).

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

21311113110 is a wasteful number, since it uses less digits than its factorization.

21311113110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45078.

The product of its (nonzero) digits is 18, while the sum is 15.

Adding to 21311113110 its reverse (1131111312), we get a palindrome (22442224422).

It can be divided in two parts, 21311 and 113110, that added together give a triangular number (134421 = T₅₁₈).

The spelling of 21311113110 in words is "twenty-one billion, three hundred eleven million, one hundred thirteen thousand, one hundred ten".