20566764013 has 4 divisors (see below), whose sum is σ = 21460971168. Its totient is φ = 19672556860.

The previous prime is 20566764007. The next prime is 20566764037. The reversal of 20566764013 is 31046766502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20566764013 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20566764613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 447103543 + ... + 447103588.

It is an arithmetic number, because the mean of its divisors is an integer number (5365242792).

Almost surely, 2^20566764013 is an apocalyptic number.

20566764013 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

20566764013 is a deficient number, since it is larger than the sum of its proper divisors (894207155).

20566764013 is an equidigital number, since it uses as much as digits as its factorization.

20566764013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 894207154.

The product of its (nonzero) digits is 181440, while the sum is 40.

The spelling of 20566764013 in words is "twenty billion, five hundred sixty-six million, seven hundred sixty-four thousand, thirteen".