21331299 has 8 divisors (see below), whose sum is σ = 31027392. Its totient is φ = 12928040.

The previous prime is 21331283. The next prime is 21331309. The reversal of 21331299 is 99213312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21331299 - 2⁴ = 21331283 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21331399) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 323169 + ... + 323234.

It is an arithmetic number, because the mean of its divisors is an integer number (3878424).

Almost surely, 2^21331299 is an apocalyptic number.

21331299 is a deficient number, since it is larger than the sum of its proper divisors (9696093).

21331299 is a wasteful number, since it uses less digits than its factorization.

21331299 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646417.

The product of its digits is 2916, while the sum is 30.

The square root of 21331299 is about 4618.5819252234. The cubic root of 21331299 is about 277.3356936603.

The spelling of 21331299 in words is "twenty-one million, three hundred thirty-one thousand, two hundred ninety-nine".