1665965489 has 2 divisors, whose sum is σ = 1665965490. Its totient is φ = 1665965488.

The previous prime is 1665965453. The next prime is 1665965491. The reversal of 1665965489 is 9845695661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 952648225 + 713317264 = 30865^2 + 26708^2 .

It is a cyclic number.

It is not a de Polignac number, because 1665965489 - 2²⁴ = 1649188273 is a prime.

Together with 1665965491, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1665965089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832982744 + 832982745.

It is an arithmetic number, because the mean of its divisors is an integer number (832982745).

Almost surely, 2^1665965489 is an apocalyptic number.

It is an amenable number.

1665965489 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665965489 is an equidigital number, since it uses as much as digits as its factorization.

1665965489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13996800, while the sum is 59.

The square root of 1665965489 is about 40816.2405054655. The cubic root of 1665965489 is about 1185.4648105648.

The spelling of 1665965489 in words is "one billion, six hundred sixty-five million, nine hundred sixty-five thousand, four hundred eighty-nine".