1660512661 has 2 divisors, whose sum is σ = 1660512662. Its totient is φ = 1660512660.

The previous prime is 1660512599. The next prime is 1660512683. The reversal of 1660512661 is 1662150661.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1645843761 + 14668900 = 40569^2 + 3830^2 .

It is a cyclic number.

It is not a de Polignac number, because 1660512661 - 2⁷ = 1660512533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1660513661) 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 as a sum of consecutive naturals, namely, 830256330 + 830256331.

It is an arithmetic number, because the mean of its divisors is an integer number (830256331).

Almost surely, 2^1660512661 is an apocalyptic number.

It is an amenable number.

1660512661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1660512661 is an equidigital number, since it uses as much as digits as its factorization.

1660512661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 1660512661 is about 40749.3884739391. The cubic root of 1660512661 is about 1184.1700256211.

The spelling of 1660512661 in words is "one billion, six hundred sixty million, five hundred twelve thousand, six hundred sixty-one".