20320523999 has 4 divisors (see below), whose sum is σ = 20664939720. Its totient is φ = 19976108280.

The previous prime is 20320523981. The next prime is 20320524079. The reversal of 20320523999 is 99932502302.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99932502302 = 2 ⋅49966251151.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20320523999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20320523969) 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, 172207772 + ... + 172207889.

It is an arithmetic number, because the mean of its divisors is an integer number (5166234930).

Almost surely, 2^20320523999 is an apocalyptic number.

20320523999 is a deficient number, since it is larger than the sum of its proper divisors (344415721).

20320523999 is an equidigital number, since it uses as much as digits as its factorization.

20320523999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344415720.

The product of its (nonzero) digits is 262440, while the sum is 44.

The spelling of 20320523999 in words is "twenty billion, three hundred twenty million, five hundred twenty-three thousand, nine hundred ninety-nine".