21884999 has 4 divisors (see below), whose sum is σ = 21946320. Its totient is φ = 21823680.

The previous prime is 21884987. The next prime is 21885013. The reversal of 21884999 is 99948812.

It is a happy number.

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 21884999 - 2¹⁶ = 21819463 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21884099) 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 3 ways as a sum of consecutive naturals, for example, 30122 + ... + 30839.

It is an arithmetic number, because the mean of its divisors is an integer number (5486580).

Almost surely, 2^21884999 is an apocalyptic number.

21884999 is a deficient number, since it is larger than the sum of its proper divisors (61321).

21884999 is an equidigital number, since it uses as much as digits as its factorization.

21884999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61320.

The product of its digits is 373248, while the sum is 50.

The square root of 21884999 is about 4678.1405494064. The cubic root of 21884999 is about 279.7148414893.

The spelling of 21884999 in words is "twenty-one million, eight hundred eighty-four thousand, nine hundred ninety-nine".