6640018897 has 2 divisors, whose sum is σ = 6640018898. Its totient is φ = 6640018896.

The previous prime is 6640018829. The next prime is 6640018907. The reversal of 6640018897 is 7988100466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4428103936 + 2211914961 = 66544^2 + 47031^2 .

It is a cyclic number.

It is not a de Polignac number, because 6640018897 - 2²³ = 6631630289 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6640018897.

It is not a weakly prime, because it can be changed into another prime (6640015897) 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, 3320009448 + 3320009449.

It is an arithmetic number, because the mean of its divisors is an integer number (3320009449).

Almost surely, 2^6640018897 is an apocalyptic number.

It is an amenable number.

6640018897 is a deficient number, since it is larger than the sum of its proper divisors (1).

6640018897 is an equidigital number, since it uses as much as digits as its factorization.

6640018897 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 580608, while the sum is 49.

The square root of 6640018897 is about 81486.3111019268. The cubic root of 6640018897 is about 1879.5610580226.

The spelling of 6640018897 in words is "six billion, six hundred forty million, eighteen thousand, eight hundred ninety-seven".