381509 has 2 divisors, whose sum is σ = 381510. Its totient is φ = 381508.

The previous prime is 381487. The next prime is 381523. The reversal of 381509 is 905183.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 372100 + 9409 = 610^2 + 97^2 .

It is a cyclic number.

It is not a de Polignac number, because 381509 - 2⁸ = 381253 is a prime.

It is a Chen prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 381509.

It is not a weakly prime, because it can be changed into another prime (381529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190754 + 190755.

It is an arithmetic number, because the mean of its divisors is an integer number (190755).

2³⁸¹⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

381509 is a deficient number, since it is larger than the sum of its proper divisors (1).

381509 is an equidigital number, since it uses as much as digits as its factorization.

381509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 381509 is about 617.6641482230. The cubic root of 381509 is about 72.5273143216.

The spelling of 381509 in words is "three hundred eighty-one thousand, five hundred nine".