21799199 has 2 divisors, whose sum is σ = 21799200. Its totient is φ = 21799198.

The previous prime is 21799189. The next prime is 21799241. The reversal of 21799199 is 99199712.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21799199 - 2²⁴ = 5021983 is a 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 (21799109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10899599 + 10899600.

It is an arithmetic number, because the mean of its divisors is an integer number (10899600).

Almost surely, 2^21799199 is an apocalyptic number.

21799199 is a deficient number, since it is larger than the sum of its proper divisors (1).

21799199 is an equidigital number, since it uses as much as digits as its factorization.

21799199 is an evil number, because the sum of its binary digits is even.

The product of its digits is 91854, while the sum is 47.

The square root of 21799199 is about 4668.9612335079. The cubic root of 21799199 is about 279.3488226586.

The spelling of 21799199 in words is "twenty-one million, seven hundred ninety-nine thousand, one hundred ninety-nine".