66217697279 has 4 divisors (see below), whose sum is σ = 66252313776. Its totient is φ = 66183080784.

The previous prime is 66217697269. The next prime is 66217697303. The reversal of 66217697279 is 97279671266.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97279671266 = 2 ⋅48639835633.

It is a cyclic number.

It is not a de Polignac number, because 66217697279 - 2⁴ = 66217697263 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 (66217697269) 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, 17305379 + ... + 17309204.

It is an arithmetic number, because the mean of its divisors is an integer number (16563078444).

Almost surely, 2^66217697279 is an apocalyptic number.

66217697279 is a deficient number, since it is larger than the sum of its proper divisors (34616497).

66217697279 is a wasteful number, since it uses less digits than its factorization.

66217697279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34616496.

The product of its digits is 24004512, while the sum is 62.

The spelling of 66217697279 in words is "sixty-six billion, two hundred seventeen million, six hundred ninety-seven thousand, two hundred seventy-nine".