21613199 has 2 divisors, whose sum is σ = 21613200. Its totient is φ = 21613198.

The previous prime is 21613177. The next prime is 21613213. The reversal of 21613199 is 99131612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21613199 - 2²⁰ = 20564623 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21613129) 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 as a sum of consecutive naturals, namely, 10806599 + 10806600.

It is an arithmetic number, because the mean of its divisors is an integer number (10806600).

Almost surely, 2^21613199 is an apocalyptic number.

21613199 is a deficient number, since it is larger than the sum of its proper divisors (1).

21613199 is an equidigital number, since it uses as much as digits as its factorization.

21613199 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2916, while the sum is 32.

The square root of 21613199 is about 4648.9997849000. Note that the first 3 decimals coincide. The cubic root of 21613199 is about 278.5520446986.

It can be divided in two parts, 21613 and 199, that added together give a palindrome (21812).

The spelling of 21613199 in words is "twenty-one million, six hundred thirteen thousand, one hundred ninety-nine".