21013123110 has 32 divisors (see below), whose sum is σ = 57635995392. Its totient is φ = 4802999520.

The previous prime is 21013123099. The next prime is 21013123121. The reversal of 21013123110 is 1132131012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21013123099) and next prime (21013123121).

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

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21013123110.

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, 50031036 + ... + 50031455.

It is an arithmetic number, because the mean of its divisors is an integer number (1801124856).

Almost surely, 2^21013123110 is an apocalyptic number.

21013123110 is an abundant number, since it is smaller than the sum of its proper divisors (36622872282).

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

21013123110 is a wasteful number, since it uses less digits than its factorization.

21013123110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100062508.

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

Adding to 21013123110 its reverse (1132131012), we get a palindrome (22145254122).

The spelling of 21013123110 in words is "twenty-one billion, thirteen million, one hundred twenty-three thousand, one hundred ten".