3991433 has 4 divisors (see below), whose sum is σ = 4012308. Its totient is φ = 3970560.

The previous prime is 3991399. The next prime is 3991441. The reversal of 3991433 is 3341993.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 635209 + 3356224 = 797^2 + 1832^2 .

It is a cyclic number.

It is not a de Polignac number, because 3991433 - 2⁶ = 3991369 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 3991433.

It is not an unprimeable number, because it can be changed into a prime (3991333) 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 3 ways as a sum of consecutive naturals, for example, 10148 + ... + 10533.

It is an arithmetic number, because the mean of its divisors is an integer number (1003077).

Almost surely, 2^3991433 is an apocalyptic number.

It is an amenable number.

3991433 is a deficient number, since it is larger than the sum of its proper divisors (20875).

3991433 is a wasteful number, since it uses less digits than its factorization.

3991433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20874.

The product of its digits is 8748, while the sum is 32.

The square root of 3991433 is about 1997.8571019970. The cubic root of 3991433 is about 158.6266969875.

The spelling of 3991433 in words is "three million, nine hundred ninety-one thousand, four hundred thirty-three".