664838825993 has 2 divisors, whose sum is σ = 664838825994. Its totient is φ = 664838825992.

The previous prime is 664838825957. The next prime is 664838826023. The reversal of 664838825993 is 399528838466.

664838825993 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 606392378944 + 58446447049 = 778712^2 + 241757^2 .

It is a cyclic number.

It is not a de Polignac number, because 664838825993 - 2⁸ = 664838825737 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (664838825293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332419412996 + 332419412997.

It is an arithmetic number, because the mean of its divisors is an integer number (332419412997).

Almost surely, 2^664838825993 is an apocalyptic number.

It is an amenable number.

664838825993 is a deficient number, since it is larger than the sum of its proper divisors (1).

664838825993 is an equidigital number, since it uses as much as digits as its factorization.

664838825993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 537477120, while the sum is 71.

The spelling of 664838825993 in words is "six hundred sixty-four billion, eight hundred thirty-eight million, eight hundred twenty-five thousand, nine hundred ninety-three".