393131663 has 4 divisors (see below), whose sum is σ = 410224368. Its totient is φ = 376038960.

The previous prime is 393131639. The next prime is 393131707. The reversal of 393131663 is 366131393.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 366131393 = 2393 ⋅153001.

It is a de Polignac number, because none of the positive numbers 2^k-393131663 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 (393134663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8546318 + ... + 8546363.

It is an arithmetic number, because the mean of its divisors is an integer number (102556092).

Almost surely, 2^393131663 is an apocalyptic number.

393131663 is a deficient number, since it is larger than the sum of its proper divisors (17092705).

393131663 is a wasteful number, since it uses less digits than its factorization.

393131663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17092704.

The product of its digits is 26244, while the sum is 35.

The square root of 393131663 is about 19827.5480834116. The cubic root of 393131663 is about 732.5647342294.

The spelling of 393131663 in words is "three hundred ninety-three million, one hundred thirty-one thousand, six hundred sixty-three".