21827256 has 64 divisors (see below), whose sum is σ = 61603200. Its totient is φ = 6384000.

The previous prime is 21827249. The next prime is 21827261. The reversal of 21827256 is 65272812.

It is a Harshad number since it is a multiple of its sum of digits (33).

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, 6231 + ... + 9081.

It is an arithmetic number, because the mean of its divisors is an integer number (962550).

Almost surely, 2^21827256 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21827256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30801600).

21827256 is an abundant number, since it is smaller than the sum of its proper divisors (39775944).

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

21827256 is a wasteful number, since it uses less digits than its factorization.

21827256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2900 (or 2896 counting only the distinct ones).

The product of its digits is 13440, while the sum is 33.

The square root of 21827256 is about 4671.9648971284. The cubic root of 21827256 is about 279.4686180355.

The spelling of 21827256 in words is "twenty-one million, eight hundred twenty-seven thousand, two hundred fifty-six".