21992359 has 4 divisors (see below), whose sum is σ = 22528800. Its totient is φ = 21455920.

The previous prime is 21992357. The next prime is 21992401. The reversal of 21992359 is 95329912.

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

It is a cyclic number.

It is not a de Polignac number, because 21992359 - 2¹ = 21992357 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21992351) 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, 268159 + ... + 268240.

It is an arithmetic number, because the mean of its divisors is an integer number (5632200).

Almost surely, 2^21992359 is an apocalyptic number.

21992359 is a deficient number, since it is larger than the sum of its proper divisors (536441).

21992359 is an equidigital number, since it uses as much as digits as its factorization.

21992359 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 536440.

The product of its digits is 43740, while the sum is 40.

The square root of 21992359 is about 4689.6011557487. The cubic root of 21992359 is about 280.1714893356.

The spelling of 21992359 in words is "twenty-one million, nine hundred ninety-two thousand, three hundred fifty-nine".