21540112 has 20 divisors (see below), whose sum is σ = 45528336. Its totient is φ = 9790880.

The previous prime is 21540083. The next prime is 21540157. The reversal of 21540112 is 21104512.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61018 + ... + 61369.

Almost surely, 2^21540112 is an apocalyptic number.

21540112 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21540112 is an abundant number, since it is smaller than the sum of its proper divisors (23988224).

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

21540112 is a wasteful number, since it uses less digits than its factorization.

21540112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122406 (or 122400 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 21540112 is about 4641.1326203848. The cubic root of 21540112 is about 278.2377070790.

Adding to 21540112 its reverse (21104512), we get a palindrome (42644624).

Subtracting from 21540112 its reverse (21104512), we obtain a square (435600 = 660²).

The spelling of 21540112 in words is "twenty-one million, five hundred forty thousand, one hundred twelve".