20385817 has 4 divisors (see below), whose sum is σ = 21043456. Its totient is φ = 19728180.

The previous prime is 20385791. The next prime is 20385823. The reversal of 20385817 is 71858302.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20385817 - 2¹⁵ = 20353049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20385887) 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, 328773 + ... + 328834.

It is an arithmetic number, because the mean of its divisors is an integer number (5260864).

Almost surely, 2^20385817 is an apocalyptic number.

It is an amenable number.

20385817 is a deficient number, since it is larger than the sum of its proper divisors (657639).

20385817 is an equidigital number, since it uses as much as digits as its factorization.

20385817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 657638.

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 20385817 is about 4515.0655587710. The cubic root of 20385817 is about 273.1761041347.

The spelling of 20385817 in words is "twenty million, three hundred eighty-five thousand, eight hundred seventeen".