166222661 has 12 divisors (see below), whose sum is σ = 184339596. Its totient is φ = 149761920.

The previous prime is 166222657. The next prime is 166222663.

166222661 is nontrivially palindromic in base 10.

166222661 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 2 ways, for example, as 5085025 + 161137636 = 2255^2 + 12694^2 .

It is not a de Polignac number, because 166222661 - 2² = 166222657 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 (166222663) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7595 + ... + 19751.

It is an arithmetic number, because the mean of its divisors is an integer number (15361633).

Almost surely, 2^166222661 is an apocalyptic number.

166222661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

166222661 is a deficient number, since it is larger than the sum of its proper divisors (18116935).

166222661 is a wasteful number, since it uses less digits than its factorization.

166222661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12292 (or 12281 counting only the distinct ones).

The product of its digits is 10368, while the sum is 32.

The square root of 166222661 is about 12892.7367536920. The cubic root of 166222661 is about 549.8320820723.

The spelling of 166222661 in words is "one hundred sixty-six million, two hundred twenty-two thousand, six hundred sixty-one".