166797661 has 4 divisors (see below), whose sum is σ = 169624800. Its totient is φ = 163970524.

The previous prime is 166797619. The next prime is 166797667.

166797661 is nontrivially palindromic in base 10.

166797661 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 166797661 - 2²¹ = 164700509 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166797667) 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, 1413481 + ... + 1413598.

It is an arithmetic number, because the mean of its divisors is an integer number (42406200).

Almost surely, 2^166797661 is an apocalyptic number.

It is an amenable number.

166797661 is a deficient number, since it is larger than the sum of its proper divisors (2827139).

166797661 is an equidigital number, since it uses as much as digits as its factorization.

166797661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2827138.

The product of its digits is 571536, while the sum is 49.

The square root of 166797661 is about 12915.0168795863. The cubic root of 166797661 is about 550.4653483122.

The spelling of 166797661 in words is "one hundred sixty-six million, seven hundred ninety-seven thousand, six hundred sixty-one".