20566351717 has 4 divisors (see below), whose sum is σ = 20568255136. Its totient is φ = 20564448300.

The previous prime is 20566351709. The next prime is 20566351721. The reversal of 20566351717 is 71715366502.

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 not a de Polignac number, because 20566351717 - 2³ = 20566351709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20566351517) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 935409 + ... + 957142.

It is an arithmetic number, because the mean of its divisors is an integer number (5142063784).

Almost surely, 2^20566351717 is an apocalyptic number.

It is an amenable number.

20566351717 is a deficient number, since it is larger than the sum of its proper divisors (1903419).

20566351717 is a wasteful number, since it uses less digits than its factorization.

20566351717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1903418.

The product of its (nonzero) digits is 264600, while the sum is 43.

The spelling of 20566351717 in words is "twenty billion, five hundred sixty-six million, three hundred fifty-one thousand, seven hundred seventeen".