3991166 has 4 divisors (see below), whose sum is σ = 5986752. Its totient is φ = 1995582.

The previous prime is 3991139. The next prime is 3991181. The reversal of 3991166 is 6611993.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 997790 + ... + 997793.

It is an arithmetic number, because the mean of its divisors is an integer number (1496688).

Almost surely, 2^3991166 is an apocalyptic number.

3991166 is a deficient number, since it is larger than the sum of its proper divisors (1995586).

3991166 is a wasteful number, since it uses less digits than its factorization.

3991166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1995585.

The product of its digits is 8748, while the sum is 35.

The square root of 3991166 is about 1997.7902792836. The cubic root of 3991166 is about 158.6231598892.

The spelling of 3991166 in words is "three million, nine hundred ninety-one thousand, one hundred sixty-six".