6696639889 has 27 divisors (see below), whose sum is σ = 7289300763. Its totient is φ = 6151222944.

The previous prime is 6696639857. The next prime is 6696639907. The reversal of 6696639889 is 9889366966.

The square root of 6696639889 is 81833.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 3801339025 + 2895300864 = 61655^2 + 53808^2 .

It is not a de Polignac number, because 6696639889 - 2⁵ = 6696639857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6696609889) 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 in 26 ways as a sum of consecutive naturals, for example, 91734757 + ... + 91734829.

Almost surely, 2^6696639889 is an apocalyptic number.

6696639889 is the 81833-rd square number.

6696639889 is the 40917-th centered octagonal number.

It is an amenable number.

6696639889 is a deficient number, since it is larger than the sum of its proper divisors (592660874).

6696639889 is an frugal number, since it uses more digits than its factorization.

6696639889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302 (or 151 counting only the distinct ones).

The product of its digits is 181398528, while the sum is 70.

The cubic root of 6696639889 is about 1884.8884293947. Note that the first 3 decimals are identical.

The spelling of 6696639889 in words is "six billion, six hundred ninety-six million, six hundred thirty-nine thousand, eight hundred eighty-nine".