3991137 has 8 divisors (see below), whose sum is σ = 5332800. Its totient is φ = 2655120.

The previous prime is 3991111. The next prime is 3991139. The reversal of 3991137 is 7311993.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 3991137 - 2¹⁰ = 3990113 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

3991137 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 3991098 and 3991107.

It is not an unprimeable number, because it can be changed into a prime (3991139) 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, 687 + ... + 2907.

It is an arithmetic number, because the mean of its divisors is an integer number (666600).

Almost surely, 2^3991137 is an apocalyptic number.

It is an amenable number.

3991137 is a deficient number, since it is larger than the sum of its proper divisors (1341663).

3991137 is a wasteful number, since it uses less digits than its factorization.

3991137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2823.

The product of its digits is 5103, while the sum is 33.

The square root of 3991137 is about 1997.7830212513. The cubic root of 3991137 is about 158.6227757005.

The spelling of 3991137 in words is "three million, nine hundred ninety-one thousand, one hundred thirty-seven".