3961991693 has 16 divisors (see below), whose sum is σ = 4365472320. Its totient is φ = 3595548880.

The previous prime is 3961991651. The next prime is 3961991711.

3961991693 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 3961991693 - 2⁸ = 3961991437 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3961991633) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 874871 + ... + 879387.

It is an arithmetic number, because the mean of its divisors is an integer number (272842020).

Almost surely, 2^3961991693 is an apocalyptic number.

It is an amenable number.

3961991693 is a deficient number, since it is larger than the sum of its proper divisors (403480627).

3961991693 is an equidigital number, since it uses as much as digits as its factorization.

3961991693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5209 (or 5187 counting only the distinct ones).

The product of its digits is 2125764, while the sum is 56.

The square root of 3961991693 is about 62944.3539406038. The cubic root of 3961991693 is about 1582.3571734230.

The spelling of 3961991693 in words is "three billion, nine hundred sixty-one million, nine hundred ninety-one thousand, six hundred ninety-three".