43149991 has 2 divisors, whose sum is σ = 43149992. Its totient is φ = 43149990.

The previous prime is 43149989. The next prime is 43150013. The reversal of 43149991 is 19994134.

43149991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 43149991 - 2¹ = 43149989 is a prime.

Together with 43149989, 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 (43149971) 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 as a sum of consecutive naturals, namely, 21574995 + 21574996.

It is an arithmetic number, because the mean of its divisors is an integer number (21574996).

Almost surely, 2^43149991 is an apocalyptic number.

43149991 is a deficient number, since it is larger than the sum of its proper divisors (1).

43149991 is an equidigital number, since it uses as much as digits as its factorization.

43149991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 40.

The square root of 43149991 is about 6568.8652749162. The cubic root of 43149991 is about 350.7466807482.

The spelling of 43149991 in words is "forty-three million, one hundred forty-nine thousand, nine hundred ninety-one".