381531091 has 2 divisors, whose sum is σ = 381531092. Its totient is φ = 381531090.

The previous prime is 381531089. The next prime is 381531169. The reversal of 381531091 is 190135183.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 381531091 - 2¹ = 381531089 is a prime.

Together with 381531089, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (381531791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190765545 + 190765546.

It is an arithmetic number, because the mean of its divisors is an integer number (190765546).

Almost surely, 2^381531091 is an apocalyptic number.

381531091 is a deficient number, since it is larger than the sum of its proper divisors (1).

381531091 is an equidigital number, since it uses as much as digits as its factorization.

381531091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 381531091 is about 19532.8208664289. The cubic root of 381531091 is about 725.2871417498.

The spelling of 381531091 in words is "three hundred eighty-one million, five hundred thirty-one thousand, ninety-one".