20566975993 has 2 divisors, whose sum is σ = 20566975994. Its totient is φ = 20566975992.

The previous prime is 20566975991. The next prime is 20566976033. The reversal of 20566975993 is 39957966502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20200368384 + 366607609 = 142128^2 + 19147^2 .

It is a cyclic number.

It is not a de Polignac number, because 20566975993 - 2¹ = 20566975991 is a prime.

Together with 20566975991, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20566975991) 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, 10283487996 + 10283487997.

It is an arithmetic number, because the mean of its divisors is an integer number (10283487997).

Almost surely, 2^20566975993 is an apocalyptic number.

It is an amenable number.

20566975993 is a deficient number, since it is larger than the sum of its proper divisors (1).

20566975993 is an equidigital number, since it uses as much as digits as its factorization.

20566975993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27556200, while the sum is 61.

The spelling of 20566975993 in words is "twenty billion, five hundred sixty-six million, nine hundred seventy-five thousand, nine hundred ninety-three".