66376311817 has 4 divisors (see below), whose sum is σ = 66378042900. Its totient is φ = 66374580736.

The previous prime is 66376311719. The next prime is 66376311851. The reversal of 66376311817 is 71811367366.

It is a happy number.

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 36917395321 + 29458916496 = 192139^2 + 171636^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66376311817 is a prime.

It is a super-2 number, since 2×66376311817² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66376311857) 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, 806692 + ... + 885157.

It is an arithmetic number, because the mean of its divisors is an integer number (16594510725).

Almost surely, 2^66376311817 is an apocalyptic number.

It is an amenable number.

66376311817 is a deficient number, since it is larger than the sum of its proper divisors (1731083).

66376311817 is a wasteful number, since it uses less digits than its factorization.

66376311817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1731082.

The product of its digits is 762048, while the sum is 49.

The spelling of 66376311817 in words is "sixty-six billion, three hundred seventy-six million, three hundred eleven thousand, eight hundred seventeen".