381188809 has 2 divisors, whose sum is σ = 381188810. Its totient is φ = 381188808.

The previous prime is 381188791. The next prime is 381188813. The reversal of 381188809 is 908881183.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 361190025 + 19998784 = 19005^2 + 4472^2 .

It is a cyclic number.

It is not a de Polignac number, because 381188809 - 2¹⁹ = 380664521 is a prime.

It is not a weakly prime, because it can be changed into another prime (381188839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190594404 + 190594405.

It is an arithmetic number, because the mean of its divisors is an integer number (190594405).

Almost surely, 2^381188809 is an apocalyptic number.

It is an amenable number.

381188809 is a deficient number, since it is larger than the sum of its proper divisors (1).

381188809 is an equidigital number, since it uses as much as digits as its factorization.

381188809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 110592, while the sum is 46.

The square root of 381188809 is about 19524.0571859437. The cubic root of 381188809 is about 725.0701851990.

The spelling of 381188809 in words is "three hundred eighty-one million, one hundred eighty-eight thousand, eight hundred nine".