21308112 has 60 divisors (see below), whose sum is σ = 68155360. Its totient is φ = 6087744.

The previous prime is 21308107. The next prime is 21308137. The reversal of 21308112 is 21180312.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9562 + ... + 11577.

Almost surely, 2^21308112 is an apocalyptic number.

It is an amenable number.

21308112 is an abundant number, since it is smaller than the sum of its proper divisors (46847248).

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

21308112 is a wasteful number, since it uses less digits than its factorization.

21308112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21160 (or 21151 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 21308112 is about 4616.0710566455. The cubic root of 21308112 is about 277.2351697910.

Adding to 21308112 its reverse (21180312), we get a palindrome (42488424).

The spelling of 21308112 in words is "twenty-one million, three hundred eight thousand, one hundred twelve".