166986366697 has 4 divisors (see below), whose sum is σ = 167519869780. Its totient is φ = 166452863616.

The previous prime is 166986366649. The next prime is 166986366709. The reversal of 166986366697 is 796663689661.

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 49454643456 + 117531723241 = 222384^2 + 342829^2 .

It is a cyclic number.

It is not a de Polignac number, because 166986366697 - 2¹⁹ = 166985842409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166986366997) 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, 266751072 + ... + 266751697.

It is an arithmetic number, because the mean of its divisors is an integer number (41879967445).

Almost surely, 2^166986366697 is an apocalyptic number.

It is an amenable number.

166986366697 is a deficient number, since it is larger than the sum of its proper divisors (533503083).

166986366697 is an equidigital number, since it uses as much as digits as its factorization.

166986366697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 533503082.

The product of its digits is 634894848, while the sum is 73.

The spelling of 166986366697 in words is "one hundred sixty-six billion, nine hundred eighty-six million, three hundred sixty-six thousand, six hundred ninety-seven".