338405891 has 2 divisors, whose sum is σ = 338405892. Its totient is φ = 338405890.

The previous prime is 338405867. The next prime is 338405909. The reversal of 338405891 is 198504833.

It is a strong prime.

It is an emirp because it is prime and its reverse (198504833) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 338405891 - 2¹⁰ = 338404867 is a prime.

It is a super-2 number, since 2×338405891² = 229037094127007762, which contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (338405191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 169202945 + 169202946.

It is an arithmetic number, because the mean of its divisors is an integer number (169202946).

Almost surely, 2^338405891 is an apocalyptic number.

338405891 is a deficient number, since it is larger than the sum of its proper divisors (1).

338405891 is an equidigital number, since it uses as much as digits as its factorization.

338405891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 41.

The square root of 338405891 is about 18395.8117787718. The cubic root of 338405891 is about 696.8606979469.

The spelling of 338405891 in words is "three hundred thirty-eight million, four hundred five thousand, eight hundred ninety-one".