20885839 has 4 divisors (see below), whose sum is σ = 22492456. Its totient is φ = 19279224.

The previous prime is 20885833. The next prime is 20885849. The reversal of 20885839 is 93858802.

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-20885839 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20885795 and 20885804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20885833) 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, 803289 + ... + 803314.

It is an arithmetic number, because the mean of its divisors is an integer number (5623114).

Almost surely, 2^20885839 is an apocalyptic number.

20885839 is a deficient number, since it is larger than the sum of its proper divisors (1606617).

20885839 is a wasteful number, since it uses less digits than its factorization.

20885839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1606616.

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

The square root of 20885839 is about 4570.1027340750. The cubic root of 20885839 is about 275.3915700061.

The spelling of 20885839 in words is "twenty million, eight hundred eighty-five thousand, eight hundred thirty-nine".