381709 has 4 divisors (see below), whose sum is σ = 383040. Its totient is φ = 380380.

The previous prime is 381707. The next prime is 381713. The reversal of 381709 is 907183.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 381709 - 2¹ = 381707 is a prime.

It is a Duffinian number.

381709 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381707) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37 + ... + 874.

It is an arithmetic number, because the mean of its divisors is an integer number (95760).

2³⁸¹⁷⁰⁹ is an apocalyptic number.

It is an amenable number.

381709 is a deficient number, since it is larger than the sum of its proper divisors (1331).

381709 is an equidigital number, since it uses as much as digits as its factorization.

381709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1330.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 381709 is about 617.8260272925. The cubic root of 381709 is about 72.5399858696.

The spelling of 381709 in words is "three hundred eighty-one thousand, seven hundred nine".