166581266 has 16 divisors (see below), whose sum is σ = 264997656. Its totient is φ = 78264576.

The previous prime is 166581263. The next prime is 166581271. The reversal of 166581266 is 662185661.

It is a happy number.

166581266 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 160554241 + 6027025 = 12671^2 + 2455^2 .

It is not an unprimeable number, because it can be changed into a prime (166581263) 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, 19400 + ... + 26636.

Almost surely, 2^166581266 is an apocalyptic number.

166581266 is a deficient number, since it is larger than the sum of its proper divisors (98416390).

166581266 is a wasteful number, since it uses less digits than its factorization.

166581266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7933.

The product of its digits is 103680, while the sum is 41.

The square root of 166581266 is about 12906.6365099510. The cubic root of 166581266 is about 550.2271964938.

The spelling of 166581266 in words is "one hundred sixty-six million, five hundred eighty-one thousand, two hundred sixty-six".