21318883 has 4 divisors (see below), whose sum is σ = 21680280. Its totient is φ = 20957488.

The previous prime is 21318881. The next prime is 21318889. The reversal of 21318883 is 38881312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21318883 - 2¹ = 21318881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21318881) 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, 180610 + ... + 180727.

It is an arithmetic number, because the mean of its divisors is an integer number (5420070).

Almost surely, 2^21318883 is an apocalyptic number.

21318883 is a deficient number, since it is larger than the sum of its proper divisors (361397).

21318883 is an equidigital number, since it uses as much as digits as its factorization.

21318883 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361396.

The product of its digits is 9216, while the sum is 34.

The square root of 21318883 is about 4617.2375940599. The cubic root of 21318883 is about 277.2818749614.

It can be divided in two parts, 21318 and 883, that added together give a square (22201 = 149²).

The spelling of 21318883 in words is "twenty-one million, three hundred eighteen thousand, eight hundred eighty-three".