166116561 has 8 divisors (see below), whose sum is σ = 238526400. Its totient is φ = 102225552.

The previous prime is 166116541. The next prime is 166116589. The reversal of 166116561 is 165611661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 166116561 - 2¹⁴ = 166100177 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (166116541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2129661 + ... + 2129738.

It is an arithmetic number, because the mean of its divisors is an integer number (29815800).

Almost surely, 2^166116561 is an apocalyptic number.

It is an amenable number.

166116561 is a deficient number, since it is larger than the sum of its proper divisors (72409839).

166116561 is a wasteful number, since it uses less digits than its factorization.

166116561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4259415.

The product of its digits is 6480, while the sum is 33.

The square root of 166116561 is about 12888.6213770131. The cubic root of 166116561 is about 549.7150711502.

The spelling of 166116561 in words is "one hundred sixty-six million, one hundred sixteen thousand, five hundred sixty-one".