20859839 has 36 divisors (see below), whose sum is σ = 28789560. Its totient is φ = 14938560.

The previous prime is 20859737. The next prime is 20859841. The reversal of 20859839 is 93895802.

It is not a de Polignac number, because 20859839 - 2⁸ = 20859583 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20859839.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20859889) 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 35 ways as a sum of consecutive naturals, for example, 90977 + ... + 91205.

It is an arithmetic number, because the mean of its divisors is an integer number (799710).

Almost surely, 2^20859839 is an apocalyptic number.

20859839 is a deficient number, since it is larger than the sum of its proper divisors (7929721).

20859839 is a wasteful number, since it uses less digits than its factorization.

20859839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280 (or 260 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 44.

The square root of 20859839 is about 4567.2572732440. The cubic root of 20859839 is about 275.2772476651.

The spelling of 20859839 in words is "twenty million, eight hundred fifty-nine thousand, eight hundred thirty-nine".