43391691 has 12 divisors (see below), whose sum is σ = 71630832. Its totient is φ = 24795216.

The previous prime is 43391681. The next prime is 43391729. The reversal of 43391691 is 19619334.

43391691 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 43391691 - 2⁵ = 43391659 is a prime.

It is not an unprimeable number, because it can be changed into a prime (43391641) 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 11 ways as a sum of consecutive naturals, for example, 344316 + ... + 344441.

It is an arithmetic number, because the mean of its divisors is an integer number (5969236).

Almost surely, 2^43391691 is an apocalyptic number.

43391691 is a deficient number, since it is larger than the sum of its proper divisors (28239141).

43391691 is a wasteful number, since it uses less digits than its factorization.

43391691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 688770 (or 688767 counting only the distinct ones).

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

The square root of 43391691 is about 6587.2369776713. The cubic root of 43391691 is about 351.4003516192.

The spelling of 43391691 in words is "forty-three million, three hundred ninety-one thousand, six hundred ninety-one".