166528470191 has 4 divisors (see below), whose sum is σ = 166914847584. Its totient is φ = 166142092800.

The previous prime is 166528470179. The next prime is 166528470193. The reversal of 166528470191 is 191074825661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 191074825661 = 293221 ⋅651641.

It is a cyclic number.

It is not a de Polignac number, because 166528470191 - 2⁶ = 166528470127 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 (166528470193) 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 in 3 ways as a sum of consecutive naturals, for example, 193188050 + ... + 193188911.

It is an arithmetic number, because the mean of its divisors is an integer number (41728711896).

Almost surely, 2^166528470191 is an apocalyptic number.

166528470191 is a deficient number, since it is larger than the sum of its proper divisors (386377393).

166528470191 is an equidigital number, since it uses as much as digits as its factorization.

166528470191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386377392.

The product of its (nonzero) digits is 725760, while the sum is 50.

Adding to 166528470191 its sum of digits (50), we get a square (166528470241 = 408079²).

The spelling of 166528470191 in words is "one hundred sixty-six billion, five hundred twenty-eight million, four hundred seventy thousand, one hundred ninety-one".