166275661 has 4 divisors (see below), whose sum is σ = 171639424. Its totient is φ = 160911900.

The previous prime is 166275653. The next prime is 166275673. The reversal of 166275661 is 166572661.

166275661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 166572661 = 661 ⋅252001.

It is a cyclic number.

It is not a de Polignac number, because 166275661 - 2³ = 166275653 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 (166275601) 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, 2681835 + ... + 2681896.

It is an arithmetic number, because the mean of its divisors is an integer number (42909856).

Almost surely, 2^166275661 is an apocalyptic number.

It is an amenable number.

166275661 is a deficient number, since it is larger than the sum of its proper divisors (5363763).

166275661 is an equidigital number, since it uses as much as digits as its factorization.

166275661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5363762.

The product of its digits is 90720, while the sum is 40.

The square root of 166275661 is about 12894.7920107305. The cubic root of 166275661 is about 549.8905137437.

The spelling of 166275661 in words is "one hundred sixty-six million, two hundred seventy-five thousand, six hundred sixty-one".