21232056 has 16 divisors (see below), whose sum is σ = 53080200. Its totient is φ = 7077344.

The previous prime is 21232049. The next prime is 21232073. The reversal of 21232056 is 65023212.

It is a congruent number.

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, 442311 + ... + 442358.

Almost surely, 2^21232056 is an apocalyptic number.

It is an amenable number.

21232056 is an abundant number, since it is smaller than the sum of its proper divisors (31848144).

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

21232056 is a wasteful number, since it uses less digits than its factorization.

21232056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 884678 (or 884674 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 21232056 is about 4607.8255175299. The cubic root of 21232056 is about 276.9049272530.

Adding to 21232056 its reverse (65023212), we get a palindrome (86255268).

The spelling of 21232056 in words is "twenty-one million, two hundred thirty-two thousand, fifty-six".