21265112 has 32 divisors (see below), whose sum is σ = 43787520. Its totient is φ = 9601440.

The previous prime is 21265093. The next prime is 21265129. The reversal of 21265112 is 21156212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13973 + ... + 15419.

It is an arithmetic number, because the mean of its divisors is an integer number (1368360).

Almost surely, 2^21265112 is an apocalyptic number.

21265112 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21265112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21893760).

21265112 is an abundant number, since it is smaller than the sum of its proper divisors (22522408).

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

21265112 is a wasteful number, since it uses less digits than its factorization.

21265112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1631 (or 1627 counting only the distinct ones).

The product of its digits is 240, while the sum is 20.

The square root of 21265112 is about 4611.4110638719. The cubic root of 21265112 is about 277.0485563504.

Subtracting from 21265112 its reverse (21156212), we obtain a square (108900 = 330²).

The spelling of 21265112 in words is "twenty-one million, two hundred sixty-five thousand, one hundred twelve".