381861 has 8 divisors (see below), whose sum is σ = 565760. Its totient is φ = 254556.

The previous prime is 381859. The next prime is 381911. The reversal of 381861 is 168183.

It is not a de Polignac number, because 381861 - 2¹ = 381859 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 14143 = 381861 / (3 + 8 + 1 + 8 + 6 + 1).

It is a Duffinian number.

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 381861.

It is not an unprimeable number, because it can be changed into a prime (381841) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 7045 + ... + 7098.

It is an arithmetic number, because the mean of its divisors is an integer number (70720).

2³⁸¹⁸⁶¹ is an apocalyptic number.

It is an amenable number.

381861 is a deficient number, since it is larger than the sum of its proper divisors (183899).

381861 is a wasteful number, since it uses less digits than its factorization.

381861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14152 (or 14146 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 381861 is about 617.9490270241. The cubic root of 381861 is about 72.5496132862.

The spelling of 381861 in words is "three hundred eighty-one thousand, eight hundred sixty-one".