3936991 has 4 divisors (see below), whose sum is σ = 3941352. Its totient is φ = 3932632.

The previous prime is 3936973. The next prime is 3936997. The reversal of 3936991 is 1996393.

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: 1996393 = 7 ⋅285199.

It is a cyclic number.

It is not a de Polignac number, because 3936991 - 2¹¹ = 3934943 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 (3936997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 265 + ... + 2818.

It is an arithmetic number, because the mean of its divisors is an integer number (985338).

Almost surely, 2^3936991 is an apocalyptic number.

3936991 is a deficient number, since it is larger than the sum of its proper divisors (4361).

3936991 is a wasteful number, since it uses less digits than its factorization.

3936991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4360.

The product of its digits is 39366, while the sum is 40.

The square root of 3936991 is about 1984.1852232088. The cubic root of 3936991 is about 157.9021853582.

The spelling of 3936991 in words is "three million, nine hundred thirty-six thousand, nine hundred ninety-one".