21723299 has 8 divisors (see below), whose sum is σ = 23938992. Its totient is φ = 19585440.

The previous prime is 21723283. The next prime is 21723301. The reversal of 21723299 is 99232712.

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 21723299 - 2⁴ = 21723283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21723239) 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, 18872 + ... + 19989.

It is an arithmetic number, because the mean of its divisors is an integer number (2992374).

Almost surely, 2^21723299 is an apocalyptic number.

21723299 is a deficient number, since it is larger than the sum of its proper divisors (2215693).

21723299 is a wasteful number, since it uses less digits than its factorization.

21723299 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38917.

The product of its digits is 13608, while the sum is 35.

The square root of 21723299 is about 4660.8259997558. The cubic root of 21723299 is about 279.0242353360.

It can be divided in two parts, 21723 and 299, that added together give a palindrome (22022).

The spelling of 21723299 in words is "twenty-one million, seven hundred twenty-three thousand, two hundred ninety-nine".