66831933217997 has 2 divisors, whose sum is σ = 66831933217998. Its totient is φ = 66831933217996.

The previous prime is 66831933217991. The next prime is 66831933218009. The reversal of 66831933217997 is 79971233913866.

66831933217997 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58338753756361 + 8493179461636 = 7637981^2 + 2914306^2 .

It is a cyclic number.

It is not a de Polignac number, because 66831933217997 - 2³² = 66827638250701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66831933217991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33415966608998 + 33415966608999.

It is an arithmetic number, because the mean of its divisors is an integer number (33415966608999).

Almost surely, 2^{66831933217997} is an apocalyptic number.

It is an amenable number.

66831933217997 is a deficient number, since it is larger than the sum of its proper divisors (1).

66831933217997 is an equidigital number, since it uses as much as digits as its factorization.

66831933217997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 555532992, while the sum is 74.

The spelling of 66831933217997 in words is "sixty-six trillion, eight hundred thirty-one billion, nine hundred thirty-three million, two hundred seventeen thousand, nine hundred ninety-seven".