21023056 has 20 divisors (see below), whose sum is σ = 40842004. Its totient is φ = 10483200.

The previous prime is 21023047. The next prime is 21023077. The reversal of 21023056 is 65032012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 46656 + 20976400 = 216^2 + 4580^2 .

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, 5176 + ... + 8296.

Almost surely, 2^21023056 is an apocalyptic number.

It is an amenable number.

21023056 is a deficient number, since it is larger than the sum of its proper divisors (19818948).

21023056 is a wasteful number, since it uses less digits than its factorization.

21023056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3550 (or 3544 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 21023056 is about 4585.0906206966. The cubic root of 21023056 is about 275.9933485760.

Adding to 21023056 its reverse (65032012), we get a palindrome (86055068).

The spelling of 21023056 in words is "twenty-one million, twenty-three thousand, fifty-six".