366666661 has 4 divisors (see below), whose sum is σ = 366714400. Its totient is φ = 366618924.

The previous prime is 366666647. The next prime is 366666689. The reversal of 366666661 is 166666663.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 166666663 = 383 ⋅435161.

It is a cyclic number.

It is not a de Polignac number, because 366666661 - 2¹⁵ = 366633893 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 (366666631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9441 + ... + 28678.

It is an arithmetic number, because the mean of its divisors is an integer number (91678600).

Almost surely, 2^366666661 is an apocalyptic number.

It is an amenable number.

366666661 is a deficient number, since it is larger than the sum of its proper divisors (47739).

366666661 is an equidigital number, since it uses as much as digits as its factorization.

366666661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47738.

The product of its digits is 839808, while the sum is 46.

The square root of 366666661 is about 19148.5420071608. The cubic root of 366666661 is about 715.7430526525.

The spelling of 366666661 in words is "three hundred sixty-six million, six hundred sixty-six thousand, six hundred sixty-one".