166991326277 has 4 divisors (see below), whose sum is σ = 166993871616. Its totient is φ = 166988780940.

The previous prime is 166991326259. The next prime is 166991326301. The reversal of 166991326277 is 772623199661.

166991326277 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 166991326277 - 2¹⁰ = 166991325253 is a prime.

It is a super-2 number, since 2×166991326277² (a number of 23 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 (166991326217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1171583 + ... + 1306364.

It is an arithmetic number, because the mean of its divisors is an integer number (41748467904).

Almost surely, 2^166991326277 is an apocalyptic number.

It is an amenable number.

166991326277 is a deficient number, since it is larger than the sum of its proper divisors (2545339).

166991326277 is an equidigital number, since it uses as much as digits as its factorization.

166991326277 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2545338.

The product of its digits is 10287648, while the sum is 59.

The spelling of 166991326277 in words is "one hundred sixty-six billion, nine hundred ninety-one million, three hundred twenty-six thousand, two hundred seventy-seven".