66663266717 has 4 divisors (see below), whose sum is σ = 66671503836. Its totient is φ = 66655029600.

The previous prime is 66663266687. The next prime is 66663266737. The reversal of 66663266717 is 71766236666.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 56403400036 + 10259866681 = 237494^2 + 101291^2 .

It is a cyclic number.

It is not a de Polignac number, because 66663266717 - 2²² = 66659072413 is a prime.

It is a super-2 number, since 2×66663266717² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66663266737) 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, 4106408 + ... + 4122609.

It is an arithmetic number, because the mean of its divisors is an integer number (16667875959).

Almost surely, 2^66663266717 is an apocalyptic number.

It is an amenable number.

66663266717 is a deficient number, since it is larger than the sum of its proper divisors (8237119).

66663266717 is an equidigital number, since it uses as much as digits as its factorization.

66663266717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8237118.

The product of its digits is 13716864, while the sum is 56.

The spelling of 66663266717 in words is "sixty-six billion, six hundred sixty-three million, two hundred sixty-six thousand, seven hundred seventeen".