6663609889 has 2 divisors, whose sum is σ = 6663609890. Its totient is φ = 6663609888.

The previous prime is 6663609877. The next prime is 6663609893. The reversal of 6663609889 is 9889063666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6659865664 + 3744225 = 81608^2 + 1935^2 .

It is a cyclic number.

It is not a de Polignac number, because 6663609889 - 2⁷ = 6663609761 is a prime.

It is not a weakly prime, because it can be changed into another prime (6663609839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3331804944 + 3331804945.

It is an arithmetic number, because the mean of its divisors is an integer number (3331804945).

Almost surely, 2^6663609889 is an apocalyptic number.

It is an amenable number.

6663609889 is a deficient number, since it is larger than the sum of its proper divisors (1).

6663609889 is an equidigital number, since it uses as much as digits as its factorization.

6663609889 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20155392, while the sum is 61.

The square root of 6663609889 is about 81630.9370827017. The cubic root of 6663609889 is about 1881.7843599945.

The spelling of 6663609889 in words is "six billion, six hundred sixty-three million, six hundred nine thousand, eight hundred eighty-nine".