393647645367668 has 6 divisors (see below), whose sum is σ = 688883379393426. Its totient is φ = 196823822683832.

The previous prime is 393647645367661. The next prime is 393647645367679. The reversal of 393647645367668 is 866763546746393.

It can be written as a sum of positive squares in only one way, i.e., 336232806569104 + 57414838798564 = 18336652^2 + 7577258^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (393647645367661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49205955670955 + ... + 49205955670962.

It is an arithmetic number, because the mean of its divisors is an integer number (114813896565571).

Almost surely, 2^{393647645367668} is an apocalyptic number.

It is an amenable number.

393647645367668 is a deficient number, since it is larger than the sum of its proper divisors (295235734025758).

393647645367668 is a wasteful number, since it uses less digits than its factorization.

393647645367668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98411911341921 (or 98411911341919 counting only the distinct ones).

The product of its digits is 59256852480, while the sum is 83.

The spelling of 393647645367668 in words is "three hundred ninety-three trillion, six hundred forty-seven billion, six hundred forty-five million, three hundred sixty-seven thousand, six hundred sixty-eight".