381688291 has 2 divisors, whose sum is σ = 381688292. Its totient is φ = 381688290.

The previous prime is 381688259. The next prime is 381688313. The reversal of 381688291 is 192886183.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 381688291 - 2⁵ = 381688259 is a prime.

It is not a weakly prime, because it can be changed into another prime (381688231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190844145 + 190844146.

It is an arithmetic number, because the mean of its divisors is an integer number (190844146).

Almost surely, 2^381688291 is an apocalyptic number.

381688291 is a deficient number, since it is larger than the sum of its proper divisors (1).

381688291 is an equidigital number, since it uses as much as digits as its factorization.

381688291 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 165888, while the sum is 46.

The square root of 381688291 is about 19536.8444483750. The cubic root of 381688291 is about 725.3867399966.

The spelling of 381688291 in words is "three hundred eighty-one million, six hundred eighty-eight thousand, two hundred ninety-one".