3991942 has 4 divisors (see below), whose sum is σ = 5987916. Its totient is φ = 1995970.

The previous prime is 3991891. The next prime is 3991943. The reversal of 3991942 is 2491993.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3991943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 997984 + ... + 997987.

It is an arithmetic number, because the mean of its divisors is an integer number (1496979).

Almost surely, 2^3991942 is an apocalyptic number.

3991942 is a deficient number, since it is larger than the sum of its proper divisors (1995974).

3991942 is a wasteful number, since it uses less digits than its factorization.

3991942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1995973.

The product of its digits is 17496, while the sum is 37.

The square root of 3991942 is about 1997.9844844242. The cubic root of 3991942 is about 158.6334395581.

The spelling of 3991942 in words is "three million, nine hundred ninety-one thousand, nine hundred forty-two".