343999991 has 2 divisors, whose sum is σ = 343999992. Its totient is φ = 343999990.

The previous prime is 343999987. The next prime is 343999993. The reversal of 343999991 is 199999343.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (199999343) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 343999991 - 2² = 343999987 is a prime.

Together with 343999993, 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 (343999993) 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, 171999995 + 171999996.

It is an arithmetic number, because the mean of its divisors is an integer number (171999996).

Almost surely, 2^343999991 is an apocalyptic number.

343999991 is a deficient number, since it is larger than the sum of its proper divisors (1).

343999991 is an equidigital number, since it uses as much as digits as its factorization.

343999991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2125764, while the sum is 56.

The square root of 343999991 is about 18547.2367483677. The cubic root of 343999991 is about 700.6796059668.

The spelling of 343999991 in words is "three hundred forty-three million, nine hundred ninety-nine thousand, nine hundred ninety-one".