660532861 has 2 divisors, whose sum is σ = 660532862. Its totient is φ = 660532860.

The previous prime is 660532823. The next prime is 660532871. The reversal of 660532861 is 168235066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 372721636 + 287811225 = 19306^2 + 16965^2 .

It is a cyclic number.

It is not a de Polignac number, because 660532861 - 2⁹ = 660532349 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 660532861.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660532871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330266430 + 330266431.

It is an arithmetic number, because the mean of its divisors is an integer number (330266431).

Almost surely, 2^660532861 is an apocalyptic number.

It is an amenable number.

660532861 is a deficient number, since it is larger than the sum of its proper divisors (1).

660532861 is an equidigital number, since it uses as much as digits as its factorization.

660532861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 660532861 is about 25700.8338580677. The cubic root of 660532861 is about 870.8930192699.

The spelling of 660532861 in words is "six hundred sixty million, five hundred thirty-two thousand, eight hundred sixty-one".