20257839 has 12 divisors (see below), whose sum is σ = 33441616. Its totient is φ = 11575872.

The previous prime is 20257837. The next prime is 20257847. The reversal of 20257839 is 93875202.

It is a happy number.

It is not a de Polignac number, because 20257839 - 2¹ = 20257837 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 (20257837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 160714 + ... + 160839.

Almost surely, 2^20257839 is an apocalyptic number.

20257839 is a deficient number, since it is larger than the sum of its proper divisors (13183777).

20257839 is a wasteful number, since it uses less digits than its factorization.

20257839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321566 (or 321563 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 20257839 is about 4500.8709157229. The cubic root of 20257839 is about 272.6032557660.

The spelling of 20257839 in words is "twenty million, two hundred fifty-seven thousand, eight hundred thirty-nine".