166661666001 has 6 divisors (see below), whose sum is σ = 240733517570. Its totient is φ = 111107777328.

The previous prime is 166661665969. The next prime is 166661666053. The reversal of 166661666001 is 100666166661.

It can be written as a sum of positive squares in only one way, i.e., 135111380625 + 31550285376 = 367575^2 + 177624^2 .

It is not a de Polignac number, because 166661666001 - 2⁵ = 166661665969 is a prime.

It is a super-2 number, since 2×166661666001² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (166661666201) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9258981436 + ... + 9258981453.

Almost surely, 2^166661666001 is an apocalyptic number.

It is an amenable number.

166661666001 is a deficient number, since it is larger than the sum of its proper divisors (74071851569).

166661666001 is a wasteful number, since it uses less digits than its factorization.

166661666001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18517962895 (or 18517962892 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 45.

The spelling of 166661666001 in words is "one hundred sixty-six billion, six hundred sixty-one million, six hundred sixty-six thousand, one".