20665734239 has 2 divisors, whose sum is σ = 20665734240. Its totient is φ = 20665734238.

The previous prime is 20665734113. The next prime is 20665734251. The reversal of 20665734239 is 93243756602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20665734239 - 2¹² = 20665730143 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20665734193 and 20665734202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20665734539) 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 as a sum of consecutive naturals, namely, 10332867119 + 10332867120.

It is an arithmetic number, because the mean of its divisors is an integer number (10332867120).

Almost surely, 2^20665734239 is an apocalyptic number.

20665734239 is a deficient number, since it is larger than the sum of its proper divisors (1).

20665734239 is an equidigital number, since it uses as much as digits as its factorization.

20665734239 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1632960, while the sum is 47.

The spelling of 20665734239 in words is "twenty billion, six hundred sixty-five million, seven hundred thirty-four thousand, two hundred thirty-nine".