21299313 has 16 divisors (see below), whose sum is σ = 32762880. Its totient is φ = 12056016.

The previous prime is 21299303. The next prime is 21299321. The reversal of 21299313 is 31399212.

It is a happy number.

It is not a de Polignac number, because 21299313 - 2⁵ = 21299281 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21299303) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2493 + ... + 6986.

It is an arithmetic number, because the mean of its divisors is an integer number (2047680).

Almost surely, 2^21299313 is an apocalyptic number.

It is an amenable number.

21299313 is a deficient number, since it is larger than the sum of its proper divisors (11463567).

21299313 is a wasteful number, since it uses less digits than its factorization.

21299313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9596.

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

The square root of 21299313 is about 4615.1178749843. The cubic root of 21299313 is about 277.1970039177.

It can be divided in two parts, 21299 and 313, that added together give a palindrome (21612).

The spelling of 21299313 in words is "twenty-one million, two hundred ninety-nine thousand, three hundred thirteen".