381689509 has 2 divisors, whose sum is σ = 381689510. Its totient is φ = 381689508.

The previous prime is 381689507. The next prime is 381689519. The reversal of 381689509 is 905986183.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 380367009 + 1322500 = 19503^2 + 1150^2 .

It is an emirp because it is prime and its reverse (905986183) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 381689509 - 2¹ = 381689507 is a prime.

It is a super-2 number, since 2×381689509² = 291373762561322162, which contains 22 as substring.

Together with 381689507, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (381689501) 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, 190844754 + 190844755.

It is an arithmetic number, because the mean of its divisors is an integer number (190844755).

Almost surely, 2^381689509 is an apocalyptic number.

It is an amenable number.

381689509 is a deficient number, since it is larger than the sum of its proper divisors (1).

381689509 is an equidigital number, since it uses as much as digits as its factorization.

381689509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 466560, while the sum is 49.

The square root of 381689509 is about 19536.8756202214. The cubic root of 381689509 is about 725.3875115862.

The spelling of 381689509 in words is "three hundred eighty-one million, six hundred eighty-nine thousand, five hundred nine".