381866 has 8 divisors (see below), whose sum is σ = 575424. Its totient is φ = 190060.

The previous prime is 381859. The next prime is 381911. The reversal of 381866 is 668183.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

381866 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 641 + ... + 1083.

It is an arithmetic number, because the mean of its divisors is an integer number (71928).

2³⁸¹⁸⁶⁶ is an apocalyptic number.

381866 is a deficient number, since it is larger than the sum of its proper divisors (193558).

381866 is a wasteful number, since it uses less digits than its factorization.

381866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 876.

The product of its digits is 6912, while the sum is 32.

The square root of 381866 is about 617.9530726520. The cubic root of 381866 is about 72.5499299341.

The spelling of 381866 in words is "three hundred eighty-one thousand, eight hundred sixty-six".