21726056 has 32 divisors (see below), whose sum is σ = 44668800. Its totient is φ = 9824640.

The previous prime is 21726013. The next prime is 21726073. The reversal of 21726056 is 65062712.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20516 + ... + 21548.

It is an arithmetic number, because the mean of its divisors is an integer number (1395900).

Almost surely, 2^21726056 is an apocalyptic number.

It is an amenable number.

21726056 is an abundant number, since it is smaller than the sum of its proper divisors (22942744).

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

21726056 is a wasteful number, since it uses less digits than its factorization.

21726056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1289 (or 1285 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 21726056 is about 4661.1217533980. The cubic root of 21726056 is about 279.0360389035.

Adding to 21726056 its reverse (65062712), we get a palindrome (86788768).

It can be divided in two parts, 2172 and 6056, that added together give a palindrome (8228).

The spelling of 21726056 in words is "twenty-one million, seven hundred twenty-six thousand, fifty-six".