3991581942 has 16 divisors (see below), whose sum is σ = 8053812720. Its totient is φ = 1318752512.

The previous prime is 3991581901. The next prime is 3991581977. The reversal of 3991581942 is 2491851993.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2942967 + ... + 2944322.

It is an arithmetic number, because the mean of its divisors is an integer number (503363295).

Almost surely, 2^3991581942 is an apocalyptic number.

3991581942 is an abundant number, since it is smaller than the sum of its proper divisors (4062230778).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3991581942 is a wasteful number, since it uses less digits than its factorization.

3991581942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5887407.

The product of its digits is 699840, while the sum is 51.

The square root of 3991581942 is about 63178.9675604152. The cubic root of 3991581942 is about 1586.2867003688.

The spelling of 3991581942 in words is "three billion, nine hundred ninety-one million, five hundred eighty-one thousand, nine hundred forty-two".