166747661 has 4 divisors (see below), whose sum is σ = 166878912. Its totient is φ = 166616412.

The previous prime is 166747621. The next prime is 166747687.

166747661 is nontrivially palindromic in base 10.

166747661 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.

It is a cyclic number.

It is not a de Polignac number, because 166747661 - 2¹⁰ = 166746637 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 (166747601) 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, 63701 + ... + 66266.

It is an arithmetic number, because the mean of its divisors is an integer number (41719728).

Almost surely, 2^166747661 is an apocalyptic number.

It is an amenable number.

166747661 is a deficient number, since it is larger than the sum of its proper divisors (131251).

166747661 is a wasteful number, since it uses less digits than its factorization.

166747661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131250.

The product of its digits is 254016, while the sum is 44.

The square root of 166747661 is about 12913.0810033857. The cubic root of 166747661 is about 550.4103395111.

The spelling of 166747661 in words is "one hundred sixty-six million, seven hundred forty-seven thousand, six hundred sixty-one".