21998183 has 4 divisors (see below), whose sum is σ = 22040928. Its totient is φ = 21955440.

The previous prime is 21998173. The next prime is 21998201. The reversal of 21998183 is 38189912.

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 21998183 - 2¹⁰ = 21997159 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21998183.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21998113) 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, 20591 + ... + 21632.

It is an arithmetic number, because the mean of its divisors is an integer number (5510232).

Almost surely, 2^21998183 is an apocalyptic number.

21998183 is a deficient number, since it is larger than the sum of its proper divisors (42745).

21998183 is an equidigital number, since it uses as much as digits as its factorization.

21998183 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42744.

The product of its digits is 31104, while the sum is 41.

The square root of 21998183 is about 4690.2220629731. Note that the first 3 decimals coincide. The cubic root of 21998183 is about 280.1962187540.

The spelling of 21998183 in words is "twenty-one million, nine hundred ninety-eight thousand, one hundred eighty-three".