21866833 has 4 divisors (see below), whose sum is σ = 22375408. Its totient is φ = 21358260.

The previous prime is 21866821. The next prime is 21866839. The reversal of 21866833 is 33866812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21866833 - 2²¹ = 19769681 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21866792 and 21866801.

It is not an unprimeable number, because it can be changed into a prime (21866839) 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, 254223 + ... + 254308.

It is an arithmetic number, because the mean of its divisors is an integer number (5593852).

Almost surely, 2^21866833 is an apocalyptic number.

It is an amenable number.

21866833 is a deficient number, since it is larger than the sum of its proper divisors (508575).

21866833 is an equidigital number, since it uses as much as digits as its factorization.

21866833 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 508574.

The product of its digits is 41472, while the sum is 37.

The square root of 21866833 is about 4676.1985629355. The cubic root of 21866833 is about 279.6374261114.

The spelling of 21866833 in words is "twenty-one million, eight hundred sixty-six thousand, eight hundred thirty-three".