381813 has 4 divisors (see below), whose sum is σ = 509088. Its totient is φ = 254540.

The previous prime is 381793. The next prime is 381817. The reversal of 381813 is 318183.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 381813 - 2⁶ = 381749 is a prime.

It is a D-number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63633 + ... + 63638.

It is an arithmetic number, because the mean of its divisors is an integer number (127272).

2³⁸¹⁸¹³ is an apocalyptic number.

It is an amenable number.

381813 is a deficient number, since it is larger than the sum of its proper divisors (127275).

381813 is a wasteful number, since it uses less digits than its factorization.

381813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127274.

The product of its digits is 576, while the sum is 24.

The square root of 381813 is about 617.9101876487. The cubic root of 381813 is about 72.5465733254.

Adding to 381813 its reverse (318183), we get a palindrome (699996).

The spelling of 381813 in words is "three hundred eighty-one thousand, eight hundred thirteen".