1660716989 has 2 divisors, whose sum is σ = 1660716990. Its totient is φ = 1660716988.

The previous prime is 1660716979. The next prime is 1660717031. The reversal of 1660716989 is 9896170661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1474176025 + 186540964 = 38395^2 + 13658^2 .

It is a cyclic number.

It is not a de Polignac number, because 1660716989 - 2⁴ = 1660716973 is a prime.

It is a super-2 number, since 2×1660716989² = 5515961835106452242, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1660716989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1660716979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830358494 + 830358495.

It is an arithmetic number, because the mean of its divisors is an integer number (830358495).

Almost surely, 2^1660716989 is an apocalyptic number.

It is an amenable number.

1660716989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1660716989 is an equidigital number, since it uses as much as digits as its factorization.

1660716989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 979776, while the sum is 53.

The square root of 1660716989 is about 40751.8955264660. The cubic root of 1660716989 is about 1184.2185947919.

The spelling of 1660716989 in words is "one billion, six hundred sixty million, seven hundred sixteen thousand, nine hundred eighty-nine".