21866313 has 8 divisors (see below), whose sum is σ = 33320128. Its totient is φ = 12495024.

The previous prime is 21866311. The next prime is 21866329. The reversal of 21866313 is 31366812.

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

It is not a de Polignac number, because 21866313 - 2¹ = 21866311 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21866311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 520606 + ... + 520647.

It is an arithmetic number, because the mean of its divisors is an integer number (4165016).

Almost surely, 2^21866313 is an apocalyptic number.

It is an amenable number.

21866313 is a deficient number, since it is larger than the sum of its proper divisors (11453815).

21866313 is a wasteful number, since it uses less digits than its factorization.

21866313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1041263.

The product of its digits is 5184, while the sum is 30.

The square root of 21866313 is about 4676.1429618864. The cubic root of 21866313 is about 279.6352094726.

The spelling of 21866313 in words is "twenty-one million, eight hundred sixty-six thousand, three hundred thirteen".