3991368 has 32 divisors (see below), whose sum is σ = 10504800. Its totient is φ = 1260288.

The previous prime is 3991333. The next prime is 3991369. The reversal of 3991368 is 8631993.

It is a super-2 number, since 2×3991368² = 31862037022848, which contains 22 as substring.

It is an Ulam number.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (3991369) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3921 + ... + 4832.

It is an arithmetic number, because the mean of its divisors is an integer number (328275).

Almost surely, 2^3991368 is an apocalyptic number.

3991368 is a gapful number since it is divisible by the number (38) formed by its first and last digit.

It is an amenable number.

3991368 is an abundant number, since it is smaller than the sum of its proper divisors (6513432).

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

3991368 is a wasteful number, since it uses less digits than its factorization.

3991368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8781 (or 8777 counting only the distinct ones).

The product of its digits is 34992, while the sum is 39.

The square root of 3991368 is about 1997.8408345011. The cubic root of 3991368 is about 158.6258359106.

The spelling of 3991368 in words is "three million, nine hundred ninety-one thousand, three hundred sixty-eight".