43027991 has 4 divisors (see below), whose sum is σ = 43050912. Its totient is φ = 43005072.

The previous prime is 43027987. The next prime is 43028033. The reversal of 43027991 is 19972034.

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

It is a cyclic number.

It is not a de Polignac number, because 43027991 - 2² = 43027987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43027961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8366 + ... + 12491.

It is an arithmetic number, because the mean of its divisors is an integer number (10762728).

Almost surely, 2^43027991 is an apocalyptic number.

43027991 is a deficient number, since it is larger than the sum of its proper divisors (22921).

43027991 is a wasteful number, since it uses less digits than its factorization.

43027991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22920.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 43027991 is about 6559.5724708246. The cubic root of 43027991 is about 350.4158078561.

The spelling of 43027991 in words is "forty-three million, twenty-seven thousand, nine hundred ninety-one".