133871813 has 2 divisors, whose sum is σ = 133871814. Its totient is φ = 133871812.

The previous prime is 133871791. The next prime is 133871819. The reversal of 133871813 is 318178331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 119749249 + 14122564 = 10943^2 + 3758^2 .

It is an emirp because it is prime and its reverse (318178331) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 133871813 - 2¹² = 133867717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133871819) 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, 66935906 + 66935907.

It is an arithmetic number, because the mean of its divisors is an integer number (66935907).

Almost surely, 2^133871813 is an apocalyptic number.

It is an amenable number.

133871813 is a deficient number, since it is larger than the sum of its proper divisors (1).

133871813 is an equidigital number, since it uses as much as digits as its factorization.

133871813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 35.

The square root of 133871813 is about 11570.2987429020. The cubic root of 133871813 is about 511.5597679163.

The spelling of 133871813 in words is "one hundred thirty-three million, eight hundred seventy-one thousand, eight hundred thirteen".