20708839 has 4 divisors (see below), whose sum is σ = 21927024. Its totient is φ = 19490656.

The previous prime is 20708833. The next prime is 20708851. The reversal of 20708839 is 93880702.

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-20708839 is a prime.

It is a super-3 number, since 3×20708839³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20708798 and 20708807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20708833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 609067 + ... + 609100.

It is an arithmetic number, because the mean of its divisors is an integer number (5481756).

Almost surely, 2^20708839 is an apocalyptic number.

20708839 is a deficient number, since it is larger than the sum of its proper divisors (1218185).

20708839 is a wasteful number, since it uses less digits than its factorization.

20708839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1218184.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 20708839 is about 4550.6965400914. The cubic root of 20708839 is about 274.6114137047.

The spelling of 20708839 in words is "twenty million, seven hundred eight thousand, eight hundred thirty-nine".