381506 has 4 divisors (see below), whose sum is σ = 572262. Its totient is φ = 190752.

The previous prime is 381487. The next prime is 381509. The reversal of 381506 is 605183.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 265225 + 116281 = 515^2 + 341^2 .

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 381506.

It is not an unprimeable number, because it can be changed into a prime (381509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95375 + ... + 95378.

2³⁸¹⁵⁰⁶ is an apocalyptic number.

381506 is a deficient number, since it is larger than the sum of its proper divisors (190756).

381506 is a wasteful number, since it uses less digits than its factorization.

381506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190755.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 381506 is about 617.6617197140. The cubic root of 381506 is about 72.5271242147.

Adding to 381506 its reverse (605183), we get a palindrome (986689).

The spelling of 381506 in words is "three hundred eighty-one thousand, five hundred six".