20806565723 has 2 divisors, whose sum is σ = 20806565724. Its totient is φ = 20806565722.

The previous prime is 20806565711. The next prime is 20806565737. The reversal of 20806565723 is 32756560802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20806565723 - 2¹² = 20806561627 is a prime.

It is not a weakly prime, because it can be changed into another prime (20806565743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10403282861 + 10403282862.

It is an arithmetic number, because the mean of its divisors is an integer number (10403282862).

Almost surely, 2^20806565723 is an apocalyptic number.

20806565723 is a deficient number, since it is larger than the sum of its proper divisors (1).

20806565723 is an equidigital number, since it uses as much as digits as its factorization.

20806565723 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 604800, while the sum is 44.

The spelling of 20806565723 in words is "twenty billion, eight hundred six million, five hundred sixty-five thousand, seven hundred twenty-three".