43431561 has 12 divisors (see below), whose sum is σ = 62919792. Its totient is φ = 28868856.

The previous prime is 43431547. The next prime is 43431571. The reversal of 43431561 is 16513434.

43431561 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 43431561 - 2⁵ = 43431529 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (43431541) 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, 3831 + ... + 10076.

It is an arithmetic number, because the mean of its divisors is an integer number (5243316).

Almost surely, 2^43431561 is an apocalyptic number.

It is an amenable number.

43431561 is a deficient number, since it is larger than the sum of its proper divisors (19488231).

43431561 is a wasteful number, since it uses less digits than its factorization.

43431561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14260 (or 14257 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

The square root of 43431561 is about 6590.2625896090. The cubic root of 43431561 is about 351.5079455141.

Adding to 43431561 its reverse (16513434), we get a palindrome (59944995).

The spelling of 43431561 in words is "forty-three million, four hundred thirty-one thousand, five hundred sixty-one".