21299331 has 8 divisors (see below), whose sum is σ = 28430080. Its totient is φ = 14184072.

The previous prime is 21299329. The next prime is 21299371. The reversal of 21299331 is 13399212.

It is a happy number.

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

It is not a de Polignac number, because 21299331 - 2¹ = 21299329 is a prime.

It is a super-2 number, since 2×21299331² = 907323002095122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21299321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 151 + ... + 6528.

It is an arithmetic number, because the mean of its divisors is an integer number (3553760).

Almost surely, 2^21299331 is an apocalyptic number.

21299331 is a deficient number, since it is larger than the sum of its proper divisors (7130749).

21299331 is a wasteful number, since it uses less digits than its factorization.

21299331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7745.

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

The square root of 21299331 is about 4615.1198250966. The cubic root of 21299331 is about 277.1970820038.

The spelling of 21299331 in words is "twenty-one million, two hundred ninety-nine thousand, three hundred thirty-one".