166020661 has 8 divisors (see below), whose sum is σ = 167321880. Its totient is φ = 164723712.

The previous prime is 166020643. The next prime is 166020697.

166020661 is nontrivially palindromic in base 10.

166020661 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 54316900 + 111703761 = 7370^2 + 10569^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 166020661 - 2²⁷ = 31802933 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 (166020061) 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, 160201 + ... + 161233.

It is an arithmetic number, because the mean of its divisors is an integer number (20915235).

Almost surely, 2^166020661 is an apocalyptic number.

It is an amenable number.

166020661 is a deficient number, since it is larger than the sum of its proper divisors (1301219).

166020661 is a wasteful number, since it uses less digits than its factorization.

166020661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2135.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 166020661 is about 12884.9005040784. The cubic root of 166020661 is about 549.6092662804.

The spelling of 166020661 in words is "one hundred sixty-six million, twenty thousand, six hundred sixty-one".