381091999 has 2 divisors, whose sum is σ = 381092000. Its totient is φ = 381091998.

The previous prime is 381091993. The next prime is 381092029. The reversal of 381091999 is 999190183.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 381091999 - 2¹⁷ = 380960927 is a prime.

It is a super-2 number, since 2×381091999² = 290462223403632002, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (381091993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190545999 + 190546000.

It is an arithmetic number, because the mean of its divisors is an integer number (190546000).

Almost surely, 2^381091999 is an apocalyptic number.

381091999 is a deficient number, since it is larger than the sum of its proper divisors (1).

381091999 is an equidigital number, since it uses as much as digits as its factorization.

381091999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 157464, while the sum is 49.

The square root of 381091999 is about 19521.5777794726. The cubic root of 381091999 is about 725.0087983078.

The spelling of 381091999 in words is "three hundred eighty-one million, ninety-one thousand, nine hundred ninety-nine".