43240991 has 2 divisors, whose sum is σ = 43240992. Its totient is φ = 43240990.

The previous prime is 43240973. The next prime is 43240993. The reversal of 43240991 is 19904234.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 43240991 - 2⁶ = 43240927 is a prime.

Together with 43240993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43240993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21620495 + 21620496.

It is an arithmetic number, because the mean of its divisors is an integer number (21620496).

Almost surely, 2^43240991 is an apocalyptic number.

43240991 is a deficient number, since it is larger than the sum of its proper divisors (1).

43240991 is an equidigital number, since it uses as much as digits as its factorization.

43240991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 43240991 is about 6575.7882417243. The cubic root of 43240991 is about 350.9930735126.

The spelling of 43240991 in words is "forty-three million, two hundred forty thousand, nine hundred ninety-one".