3991388 has 12 divisors (see below), whose sum is σ = 7003920. Its totient is φ = 1990272.

The previous prime is 3991369. The next prime is 3991399. The reversal of 3991388 is 8831993.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 620 + ... + 2892.

It is an arithmetic number, because the mean of its divisors is an integer number (583660).

Almost surely, 2^3991388 is an apocalyptic number.

It is an amenable number.

3991388 is a deficient number, since it is larger than the sum of its proper divisors (3012532).

3991388 is a wasteful number, since it uses less digits than its factorization.

3991388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2716 (or 2714 counting only the distinct ones).

The product of its digits is 46656, while the sum is 41.

The square root of 3991388 is about 1997.8458398986. The cubic root of 3991388 is about 158.6261008584.

The spelling of 3991388 in words is "three million, nine hundred ninety-one thousand, three hundred eighty-eight".