21989883 has 4 divisors (see below), whose sum is σ = 29319848. Its totient is φ = 14659920.

The previous prime is 21989879. The next prime is 21989893. The reversal of 21989883 is 38898912.

It is a happy number.

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

It is not a de Polignac number, because 21989883 - 2² = 21989879 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21989833) 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, 3664978 + ... + 3664983.

It is an arithmetic number, because the mean of its divisors is an integer number (7329962).

Almost surely, 2^21989883 is an apocalyptic number.

21989883 is a deficient number, since it is larger than the sum of its proper divisors (7329965).

21989883 is an equidigital number, since it uses as much as digits as its factorization.

21989883 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7329964.

The product of its digits is 248832, while the sum is 48.

The square root of 21989883 is about 4689.3371599833. The cubic root of 21989883 is about 280.1609746133.

The spelling of 21989883 in words is "twenty-one million, nine hundred eighty-nine thousand, eight hundred eighty-three".