21992199 has 16 divisors (see below), whose sum is σ = 29982432. Its totient is φ = 14335488.

The previous prime is 21992197. The next prime is 21992207. The reversal of 21992199 is 99129912.

It is not a de Polignac number, because 21992199 - 2¹ = 21992197 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21992199.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21992197) 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 15 ways as a sum of consecutive naturals, for example, 29637 + ... + 30369.

It is an arithmetic number, because the mean of its divisors is an integer number (1873902).

Almost surely, 2^21992199 is an apocalyptic number.

21992199 is a deficient number, since it is larger than the sum of its proper divisors (7990233).

21992199 is a wasteful number, since it uses less digits than its factorization.

21992199 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 946.

The product of its digits is 26244, while the sum is 42.

The square root of 21992199 is about 4689.5840966977. The cubic root of 21992199 is about 280.1708098944.

The spelling of 21992199 in words is "twenty-one million, nine hundred ninety-two thousand, one hundred ninety-nine".