381909 has 16 divisors (see below), whose sum is σ = 566784. Its totient is φ = 226800.

The previous prime is 381859. The next prime is 381911. The reversal of 381909 is 909183.

It is a happy number.

381909 is nontrivially palindromic in base 16.

It is not a de Polignac number, because 381909 - 2¹³ = 373717 is a prime.

381909 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381949) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2262 + ... + 2424.

It is an arithmetic number, because the mean of its divisors is an integer number (35424).

2³⁸¹⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

381909 is a deficient number, since it is larger than the sum of its proper divisors (184875).

381909 is a wasteful number, since it uses less digits than its factorization.

381909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 381909 is about 617.9878639585. The cubic root of 381909 is about 72.5526529922.

The spelling of 381909 in words is "three hundred eighty-one thousand, nine hundred nine".