391243280797 has 4 divisors (see below), whose sum is σ = 391244553756. Its totient is φ = 391242007840.

The previous prime is 391243280759. The next prime is 391243280881. The reversal of 391243280797 is 797082342193.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 797082342193 = 7691 ⋅103638323.

It can be written as a sum of positive squares in 2 ways, for example, as 217882634841 + 173360645956 = 466779^2 + 416366^2 .

It is a cyclic number.

It is not a de Polignac number, because 391243280797 - 2¹⁵ = 391243248029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391243280737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 141633 + ... + 895849.

It is an arithmetic number, because the mean of its divisors is an integer number (97811138439).

Almost surely, 2^391243280797 is an apocalyptic number.

It is an amenable number.

391243280797 is a deficient number, since it is larger than the sum of its proper divisors (1272959).

391243280797 is an equidigital number, since it uses as much as digits as its factorization.

391243280797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1272958.

The product of its (nonzero) digits is 4572288, while the sum is 55.

The spelling of 391243280797 in words is "three hundred ninety-one billion, two hundred forty-three million, two hundred eighty thousand, seven hundred ninety-seven".