21884287 has 8 divisors (see below), whose sum is σ = 23285232. Its totient is φ = 20496000.

The previous prime is 21884273. The next prime is 21884297. The reversal of 21884287 is 78248812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21884287 - 2¹⁵ = 21851519 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21884227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 537 + ... + 6637.

It is an arithmetic number, because the mean of its divisors is an integer number (2910654).

Almost surely, 2^21884287 is an apocalyptic number.

21884287 is a deficient number, since it is larger than the sum of its proper divisors (1400945).

21884287 is a wasteful number, since it uses less digits than its factorization.

21884287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6329.

The product of its digits is 57344, while the sum is 40.

The square root of 21884287 is about 4678.0644501759. The cubic root of 21884287 is about 279.7118080701.

The spelling of 21884287 in words is "twenty-one million, eight hundred eighty-four thousand, two hundred eighty-seven".