21999299 has 4 divisors (see below), whose sum is σ = 25142064. Its totient is φ = 18856536.

The previous prime is 21999281. The next prime is 21999301. The reversal of 21999299 is 99299912.

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 21999299 - 2¹² = 21995203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21999269) 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, 1571372 + ... + 1571385.

It is an arithmetic number, because the mean of its divisors is an integer number (6285516).

Almost surely, 2^21999299 is an apocalyptic number.

21999299 is a deficient number, since it is larger than the sum of its proper divisors (3142765).

21999299 is an equidigital number, since it uses as much as digits as its factorization.

21999299 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3142764.

The product of its digits is 236196, while the sum is 50.

The square root of 21999299 is about 4690.3410323771. The cubic root of 21999299 is about 280.2009569285.

The spelling of 21999299 in words is "twenty-one million, nine hundred ninety-nine thousand, two hundred ninety-nine".