3991266 has 12 divisors (see below), whose sum is σ = 8647782. Its totient is φ = 1330416.

The previous prime is 3991261. The next prime is 3991279. The reversal of 3991266 is 6621993.

3991266 is a `hidden beast` number, since 399 + 1 + 266 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2792241 + 1199025 = 1671^2 + 1095^2 .

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 3991266.

It is not an unprimeable number, because it can be changed into a prime (3991261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 110851 + ... + 110886.

Almost surely, 2^3991266 is an apocalyptic number.

3991266 is an abundant number, since it is smaller than the sum of its proper divisors (4656516).

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

3991266 is a wasteful number, since it uses less digits than its factorization.

3991266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221745 (or 221742 counting only the distinct ones).

The product of its digits is 17496, while the sum is 36.

The square root of 3991266 is about 1997.8153067789. The cubic root of 3991266 is about 158.6244846636.

The spelling of 3991266 in words is "three million, nine hundred ninety-one thousand, two hundred sixty-six".