399245766991 has 2 divisors, whose sum is σ = 399245766992. Its totient is φ = 399245766990.

The previous prime is 399245766967. The next prime is 399245767001. The reversal of 399245766991 is 199667542993.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399245766991 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 399245766991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399245766191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199622883495 + 199622883496.

It is an arithmetic number, because the mean of its divisors is an integer number (199622883496).

Almost surely, 2^399245766991 is an apocalyptic number.

399245766991 is a deficient number, since it is larger than the sum of its proper divisors (1).

399245766991 is an equidigital number, since it uses as much as digits as its factorization.

399245766991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 198404640, while the sum is 70.

The spelling of 399245766991 in words is "three hundred ninety-nine billion, two hundred forty-five million, seven hundred sixty-six thousand, nine hundred ninety-one".