166570861 has 4 divisors (see below), whose sum is σ = 167491324. Its totient is φ = 165650400.

The previous prime is 166570849. The next prime is 166570871. The reversal of 166570861 is 168075661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 168075661 = 13 ⋅12928897.

It can be written as a sum of positive squares in 2 ways, for example, as 43494025 + 123076836 = 6595^2 + 11094^2 .

It is a cyclic number.

It is not a de Polignac number, because 166570861 - 2⁵ = 166570829 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 (166570871) 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, 459960 + ... + 460321.

It is an arithmetic number, because the mean of its divisors is an integer number (41872831).

Almost surely, 2^166570861 is an apocalyptic number.

It is an amenable number.

166570861 is a deficient number, since it is larger than the sum of its proper divisors (920463).

166570861 is an equidigital number, since it uses as much as digits as its factorization.

166570861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 920462.

The product of its (nonzero) digits is 60480, while the sum is 40.

The square root of 166570861 is about 12906.2334164542. The cubic root of 166570861 is about 550.2157401572.

The spelling of 166570861 in words is "one hundred sixty-six million, five hundred seventy thousand, eight hundred sixty-one".