8531381 has 2 divisors, whose sum is σ = 8531382. Its totient is φ = 8531380.

The previous prime is 8531371. The next prime is 8531389. The reversal of 8531381 is 1831358.

8531381 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6100900 + 2430481 = 2470^2 + 1559^2 .

It is a cyclic number.

It is not a de Polignac number, because 8531381 - 2⁶ = 8531317 is a prime.

It is a super-2 number, since 2×8531381² = 145568923534322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8531389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4265690 + 4265691.

It is an arithmetic number, because the mean of its divisors is an integer number (4265691).

Almost surely, 2^8531381 is an apocalyptic number.

It is an amenable number.

8531381 is a deficient number, since it is larger than the sum of its proper divisors (1).

8531381 is an equidigital number, since it uses as much as digits as its factorization.

8531381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2880, while the sum is 29.

The square root of 8531381 is about 2920.8527864307. The cubic root of 8531381 is about 204.3335964970. Note that the first 3 decimals are identical.

The spelling of 8531381 in words is "eight million, five hundred thirty-one thousand, three hundred eighty-one".