6338791661 has 2 divisors, whose sum is σ = 6338791662. Its totient is φ = 6338791660.

The previous prime is 6338791643. The next prime is 6338791687. The reversal of 6338791661 is 1661978336.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3549895561 + 2788896100 = 59581^2 + 52810^2 .

It is a cyclic number.

It is not a de Polignac number, because 6338791661 - 2⁶ = 6338791597 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6338791691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3169395830 + 3169395831.

It is an arithmetic number, because the mean of its divisors is an integer number (3169395831).

Almost surely, 2^6338791661 is an apocalyptic number.

It is an amenable number.

6338791661 is a deficient number, since it is larger than the sum of its proper divisors (1).

6338791661 is an equidigital number, since it uses as much as digits as its factorization.

6338791661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 979776, while the sum is 50.

The square root of 6338791661 is about 79616.5288178278. The cubic root of 6338791661 is about 1850.6977315566.

The spelling of 6338791661 in words is "six billion, three hundred thirty-eight million, seven hundred ninety-one thousand, six hundred sixty-one".