20398839 has 4 divisors (see below), whose sum is σ = 27198456. Its totient is φ = 13599224.

The previous prime is 20398831. The next prime is 20398871. The reversal of 20398839 is 93889302.

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

It is a cyclic number.

It is not a de Polignac number, because 20398839 - 2³ = 20398831 is a prime.

It is a super-2 number, since 2×20398839² = 832225265095842, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20398839.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20398831) 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, 3399804 + ... + 3399809.

It is an arithmetic number, because the mean of its divisors is an integer number (6799614).

Almost surely, 2^20398839 is an apocalyptic number.

20398839 is a deficient number, since it is larger than the sum of its proper divisors (6799617).

20398839 is an equidigital number, since it uses as much as digits as its factorization.

20398839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6799616.

The product of its (nonzero) digits is 93312, while the sum is 42.

The square root of 20398839 is about 4516.5073895655. The cubic root of 20398839 is about 273.2342579982.

It can be divided in two parts, 2039 and 8839, that added together give a triangular number (10878 = T₁₄₇).

The spelling of 20398839 in words is "twenty million, three hundred ninety-eight thousand, eight hundred thirty-nine".