20666333517 has 4 divisors (see below), whose sum is σ = 27555111360. Its totient is φ = 13777555676.

The previous prime is 20666333503. The next prime is 20666333521. The reversal of 20666333517 is 71533366602.

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 20666333517 - 2¹⁵ = 20666300749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20666333617) 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, 3444388917 + ... + 3444388922.

It is an arithmetic number, because the mean of its divisors is an integer number (6888777840).

Almost surely, 2^20666333517 is an apocalyptic number.

It is an amenable number.

20666333517 is a deficient number, since it is larger than the sum of its proper divisors (6888777843).

20666333517 is an equidigital number, since it uses as much as digits as its factorization.

20666333517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6888777842.

The product of its (nonzero) digits is 408240, while the sum is 42.

The spelling of 20666333517 in words is "twenty billion, six hundred sixty-six million, three hundred thirty-three thousand, five hundred seventeen".