166404661 has 2 divisors, whose sum is σ = 166404662. Its totient is φ = 166404660.

The previous prime is 166404649. The next prime is 166404713.

166404661 is nontrivially palindromic in base 10.

166404661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 161137636 + 5267025 = 12694^2 + 2295^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 166404661 - 2¹³ = 166396469 is a prime.

It is a super-2 number, since 2×166404661² = 55381022405049842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166404631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83202330 + 83202331.

It is an arithmetic number, because the mean of its divisors is an integer number (83202331).

Almost surely, 2^166404661 is an apocalyptic number.

It is an amenable number.

166404661 is a deficient number, since it is larger than the sum of its proper divisors (1).

166404661 is an equidigital number, since it uses as much as digits as its factorization.

166404661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 166404661 is about 12899.7930603557. The cubic root of 166404661 is about 550.0326823554.

The spelling of 166404661 in words is "one hundred sixty-six million, four hundred four thousand, six hundred sixty-one".