166171801 has 4 divisors (see below), whose sum is σ = 169307172. Its totient is φ = 163036432.

The previous prime is 166171793. The next prime is 166171829. The reversal of 166171801 is 108171661.

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 43494025 + 122677776 = 6595^2 + 11076^2 .

It is a cyclic number.

It is not a de Polignac number, because 166171801 - 2³ = 166171793 is a prime.

It is a super-2 number, since 2×166171801² = 55226134895167202, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166172801) 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, 1567606 + ... + 1567711.

It is an arithmetic number, because the mean of its divisors is an integer number (42326793).

Almost surely, 2^166171801 is an apocalyptic number.

It is an amenable number.

166171801 is a deficient number, since it is larger than the sum of its proper divisors (3135371).

166171801 is an equidigital number, since it uses as much as digits as its factorization.

166171801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3135370.

The product of its (nonzero) digits is 2016, while the sum is 31.

The square root of 166171801 is about 12890.7641744002. The cubic root of 166171801 is about 549.7759980379.

The spelling of 166171801 in words is "one hundred sixty-six million, one hundred seventy-one thousand, eight hundred one".