21709299 has 8 divisors (see below), whose sum is σ = 29108160. Its totient is φ = 14391656.

The previous prime is 21709271. The next prime is 21709301. The reversal of 21709299 is 99290712.

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 21709299 - 2⁹ = 21708787 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21709099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19677 + ... + 20750.

It is an arithmetic number, because the mean of its divisors is an integer number (3638520).

Almost surely, 2^21709299 is an apocalyptic number.

21709299 is a deficient number, since it is larger than the sum of its proper divisors (7398861).

21709299 is a wasteful number, since it uses less digits than its factorization.

21709299 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40609.

The product of its (nonzero) digits is 20412, while the sum is 39.

The square root of 21709299 is about 4659.3238779892. The cubic root of 21709299 is about 278.9642816005.

The spelling of 21709299 in words is "twenty-one million, seven hundred nine thousand, two hundred ninety-nine".