21112056 has 64 divisors (see below), whose sum is σ = 67027200. Its totient is φ = 6031584.

The previous prime is 21112043. The next prime is 21112061. The reversal of 21112056 is 65021112.

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 15 ways as a sum of consecutive naturals, for example, 5470 + ... + 8493.

It is an arithmetic number, because the mean of its divisors is an integer number (1047300).

Almost surely, 2^21112056 is an apocalyptic number.

It is an amenable number.

21112056 is an abundant number, since it is smaller than the sum of its proper divisors (45915144).

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

21112056 is a wasteful number, since it uses less digits than its factorization.

21112056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13985 (or 13975 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 21112056 is about 4594.7857403801. The cubic root of 21112056 is about 276.3822680348.

Adding to 21112056 its reverse (65021112), we get a palindrome (86133168).

The spelling of 21112056 in words is "twenty-one million, one hundred twelve thousand, fifty-six".