381645 has 32 divisors (see below), whose sum is σ = 743040. Its totient is φ = 184320.

The previous prime is 381637. The next prime is 381659. The reversal of 381645 is 546183.

It is not a de Polignac number, because 381645 - 2³ = 381637 is a prime.

It is a super-3 number, since 3×381645³ = 166763109959733375, which contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

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 381645.

It is an unprimeable 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 31 ways as a sum of consecutive naturals, for example, 1357 + ... + 1613.

It is an arithmetic number, because the mean of its divisors is an integer number (23220).

2³⁸¹⁶⁴⁵ is an apocalyptic number.

It is an amenable number.

381645 is a deficient number, since it is larger than the sum of its proper divisors (361395).

381645 is a wasteful number, since it uses less digits than its factorization.

381645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282 (or 276 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 381645 is about 617.7742306053. The cubic root of 381645 is about 72.5359314559.

The spelling of 381645 in words is "three hundred eighty-one thousand, six hundred forty-five".