166000661 has 2 divisors, whose sum is σ = 166000662. Its totient is φ = 166000660.

The previous prime is 166000657. The next prime is 166000687.

166000661 is nontrivially palindromic in base 10.

166000661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (166000687) can be obtained adding 166000661 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 161442436 + 4558225 = 12706^2 + 2135^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 166000661 - 2² = 166000657 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 166000661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166000621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83000330 + 83000331.

It is an arithmetic number, because the mean of its divisors is an integer number (83000331).

Almost surely, 2^166000661 is an apocalyptic number.

It is an amenable number.

166000661 is a deficient number, since it is larger than the sum of its proper divisors (1).

166000661 is an equidigital number, since it uses as much as digits as its factorization.

166000661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 166000661 is about 12884.1243784745. The cubic root of 166000661 is about 549.5871954797.

It can be divided in two parts, 166000 and 661, that added together give a palindrome (166661).

The spelling of 166000661 in words is "one hundred sixty-six million, six hundred sixty-one", and thus it is an aban number.