86666661 has 12 divisors (see below), whose sum is σ = 128239020. Its totient is φ = 56368320.

The previous prime is 86666641. The next prime is 86666677. The reversal of 86666661 is 16666668.

It can be written as a sum of positive squares in 2 ways, for example, as 3218436 + 83448225 = 1794^2 + 9135^2 .

It is not a de Polignac number, because 86666661 - 2¹⁸ = 86404517 is a prime.

It is a super-2 number, since 2×86666661² = 15022220257777842, which contains 22 as substring.

It is a Curzon number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86666621) 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, 117066 + ... + 117803.

It is an arithmetic number, because the mean of its divisors is an integer number (10686585).

Almost surely, 2^86666661 is an apocalyptic number.

It is an amenable number.

86666661 is a deficient number, since it is larger than the sum of its proper divisors (41572359).

86666661 is a wasteful number, since it uses less digits than its factorization.

86666661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234916 (or 234913 counting only the distinct ones).

The product of its digits is 373248, while the sum is 45.

The square root of 86666661 is about 9309.4930581638. The cubic root of 86666661 is about 442.5381217755.

The spelling of 86666661 in words is "eighty-six million, six hundred sixty-six thousand, six hundred sixty-one".