3931991393 has 8 divisors (see below), whose sum is σ = 4290353760. Its totient is φ = 3573780480.

The previous prime is 3931991363. The next prime is 3931991417.

It is a happy number.

3931991393 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3931991393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3931991363) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20321 + ... + 90977.

It is an arithmetic number, because the mean of its divisors is an integer number (536294220).

Almost surely, 2^3931991393 is an apocalyptic number.

It is an amenable number.

3931991393 is a deficient number, since it is larger than the sum of its proper divisors (358362367).

3931991393 is a wasteful number, since it uses less digits than its factorization.

3931991393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75727.

The product of its digits is 531441, while the sum is 50.

The square root of 3931991393 is about 62705.5929961594. The cubic root of 3931991393 is about 1578.3531675366.

The spelling of 3931991393 in words is "three billion, nine hundred thirty-one million, nine hundred ninety-one thousand, three hundred ninety-three".