231140809 has 2 divisors, whose sum is σ = 231140810. Its totient is φ = 231140808.

The previous prime is 231140779. The next prime is 231140827. The reversal of 231140809 is 908041132.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 178142409 + 52998400 = 13347^2 + 7280^2 .

It is a cyclic number.

It is not a de Polignac number, because 231140809 - 2¹⁹ = 230616521 is a prime.

It is not a weakly prime, because it can be changed into another prime (231140839) 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, 115570404 + 115570405.

It is an arithmetic number, because the mean of its divisors is an integer number (115570405).

Almost surely, 2^231140809 is an apocalyptic number.

It is an amenable number.

231140809 is a deficient number, since it is larger than the sum of its proper divisors (1).

231140809 is an equidigital number, since it uses as much as digits as its factorization.

231140809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 231140809 is about 15203.3157238808. The cubic root of 231140809 is about 613.7038903310.

The spelling of 231140809 in words is "two hundred thirty-one million, one hundred forty thousand, eight hundred nine".