166571887 has 4 divisors (see below), whose sum is σ = 166611016. Its totient is φ = 166532760.

The previous prime is 166571863. The next prime is 166571903. The reversal of 166571887 is 788175661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 166571887 - 2²³ = 158183279 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 166571887.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166571827) 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, 12273 + ... + 21994.

It is an arithmetic number, because the mean of its divisors is an integer number (41652754).

Almost surely, 2^166571887 is an apocalyptic number.

166571887 is a deficient number, since it is larger than the sum of its proper divisors (39129).

166571887 is an equidigital number, since it uses as much as digits as its factorization.

166571887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39128.

The product of its digits is 564480, while the sum is 49.

The square root of 166571887 is about 12906.2731646281. The cubic root of 166571887 is about 550.2168698470.

The spelling of 166571887 in words is "one hundred sixty-six million, five hundred seventy-one thousand, eight hundred eighty-seven".