20823399 has 24 divisors (see below), whose sum is σ = 31682560. Its totient is φ = 13664376.

The previous prime is 20823359. The next prime is 20823409. The reversal of 20823399 is 99332802.

It is not a de Polignac number, because 20823399 - 2⁹ = 20822887 is a prime.

It is a super-2 number, since 2×20823399² = 867227891826402, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20823359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15642 + ... + 16920.

Almost surely, 2^20823399 is an apocalyptic number.

20823399 is a deficient number, since it is larger than the sum of its proper divisors (10859161).

20823399 is an equidigital number, since it uses as much as digits as its factorization.

20823399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1361 (or 1349 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 20823399 is about 4563.2662644207. The cubic root of 20823399 is about 275.1168605262.

The spelling of 20823399 in words is "twenty million, eight hundred twenty-three thousand, three hundred ninety-nine".