20724547839 has 4 divisors (see below), whose sum is σ = 27632730456. Its totient is φ = 13816365224.

The previous prime is 20724547829. The next prime is 20724547859. The reversal of 20724547839 is 93874542702.

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 20724547839 - 2⁵ = 20724547807 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20724547791 and 20724547800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20724547829) 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, 3454091304 + ... + 3454091309.

It is an arithmetic number, because the mean of its divisors is an integer number (6908182614).

Almost surely, 2^20724547839 is an apocalyptic number.

20724547839 is a deficient number, since it is larger than the sum of its proper divisors (6908182617).

20724547839 is an equidigital number, since it uses as much as digits as its factorization.

20724547839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6908182616.

The product of its (nonzero) digits is 3386880, while the sum is 51.

The spelling of 20724547839 in words is "twenty billion, seven hundred twenty-four million, five hundred forty-seven thousand, eight hundred thirty-nine".