393721368121 has 2 divisors, whose sum is σ = 393721368122. Its totient is φ = 393721368120.

The previous prime is 393721368097. The next prime is 393721368203. The reversal of 393721368121 is 121863127393.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 297500430096 + 96220938025 = 545436^2 + 310195^2 .

It is a cyclic number.

It is not a de Polignac number, because 393721368121 - 2⁹ = 393721367609 is a prime.

It is not a weakly prime, because it can be changed into another prime (393721368421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 196860684060 + 196860684061.

It is an arithmetic number, because the mean of its divisors is an integer number (196860684061).

Almost surely, 2^393721368121 is an apocalyptic number.

It is an amenable number.

393721368121 is a deficient number, since it is larger than the sum of its proper divisors (1).

393721368121 is an equidigital number, since it uses as much as digits as its factorization.

393721368121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 46.

The spelling of 393721368121 in words is "three hundred ninety-three billion, seven hundred twenty-one million, three hundred sixty-eight thousand, one hundred twenty-one".