21117299 has 4 divisors (see below), whose sum is σ = 24134064. Its totient is φ = 18100536.

The previous prime is 21117277. The next prime is 21117311. The reversal of 21117299 is 99271112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21117299 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21117209) 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, 1508372 + ... + 1508385.

It is an arithmetic number, because the mean of its divisors is an integer number (6033516).

Almost surely, 2^21117299 is an apocalyptic number.

21117299 is a deficient number, since it is larger than the sum of its proper divisors (3016765).

21117299 is an equidigital number, since it uses as much as digits as its factorization.

21117299 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3016764.

The product of its digits is 2268, while the sum is 32.

The square root of 21117299 is about 4595.3562429914. The cubic root of 21117299 is about 276.4051452049.

The spelling of 21117299 in words is "twenty-one million, one hundred seventeen thousand, two hundred ninety-nine".