381618 has 32 divisors (see below), whose sum is σ = 875520. Its totient is φ = 123120.

The previous prime is 381607. The next prime is 381629. The reversal of 381618 is 816183.

It is an interprime number because it is at equal distance from previous prime (381607) and next prime (381629).

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

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 381591 and 381600.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1903 + ... + 2093.

It is an arithmetic number, because the mean of its divisors is an integer number (27360).

2³⁸¹⁶¹⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 381618, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (437760).

381618 is an abundant number, since it is smaller than the sum of its proper divisors (493902).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

381618 is a wasteful number, since it uses less digits than its factorization.

381618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239 (or 233 counting only the distinct ones).

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

The square root of 381618 is about 617.7523775754. The cubic root of 381618 is about 72.5342208642.

It can be divided in two parts, 381 and 618, that added together give a palindrome (999).

The spelling of 381618 in words is "three hundred eighty-one thousand, six hundred eighteen".