21827288 has 16 divisors (see below), whose sum is σ = 46772880. Its totient is φ = 9354528.

The previous prime is 21827287. The next prime is 21827329. The reversal of 21827288 is 88272812.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21827287) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194831 + ... + 194942.

It is an arithmetic number, because the mean of its divisors is an integer number (2923305).

Almost surely, 2^21827288 is an apocalyptic number.

21827288 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21827288 is an abundant number, since it is smaller than the sum of its proper divisors (24945592).

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

21827288 is a wasteful number, since it uses less digits than its factorization.

21827288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389786 (or 389782 counting only the distinct ones).

The product of its digits is 28672, while the sum is 38.

The square root of 21827288 is about 4671.9683218104. The cubic root of 21827288 is about 279.4687546077.

The spelling of 21827288 in words is "twenty-one million, eight hundred twenty-seven thousand, two hundred eighty-eight".