20388859 has 4 divisors (see below), whose sum is σ = 20408704. Its totient is φ = 20369016.

The previous prime is 20388853. The next prime is 20388869. The reversal of 20388859 is 95888302.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20388859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20388853) 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 3 ways as a sum of consecutive naturals, for example, 8292 + ... + 10465.

It is an arithmetic number, because the mean of its divisors is an integer number (5102176).

Almost surely, 2^20388859 is an apocalyptic number.

20388859 is a deficient number, since it is larger than the sum of its proper divisors (19845).

20388859 is a wasteful number, since it uses less digits than its factorization.

20388859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19844.

The product of its (nonzero) digits is 138240, while the sum is 43.

The square root of 20388859 is about 4515.4024183897. The cubic root of 20388859 is about 273.1896913651.

The spelling of 20388859 in words is "twenty million, three hundred eighty-eight thousand, eight hundred fifty-nine".