243400139 has 2 divisors, whose sum is σ = 243400140. Its totient is φ = 243400138.

The previous prime is 243400123. The next prime is 243400147. The reversal of 243400139 is 931004342.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 243400139 - 2⁴ = 243400123 is a prime.

It is not a weakly prime, because it can be changed into another prime (243400109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121700069 + 121700070.

It is an arithmetic number, because the mean of its divisors is an integer number (121700070).

Almost surely, 2^243400139 is an apocalyptic number.

243400139 is a deficient number, since it is larger than the sum of its proper divisors (1).

243400139 is an equidigital number, since it uses as much as digits as its factorization.

243400139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 243400139 is about 15601.2864533666. The cubic root of 243400139 is about 624.3674786962.

The spelling of 243400139 in words is "two hundred forty-three million, four hundred thousand, one hundred thirty-nine".