361805 has 6 divisors (see below), whose sum is σ = 435786. Its totient is φ = 288368.

The previous prime is 361799. The next prime is 361807. The reversal of 361805 is 508163.

It can be written as a sum of positive squares in 3 ways, for example, as 14884 + 346921 = 122^2 + 589^2 .

It is not a de Polignac number, because 361805 - 2⁴ = 361789 is a prime.

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 361805.

It is not an unprimeable number, because it can be changed into a prime (361807) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1211 + ... + 1479.

It is an arithmetic number, because the mean of its divisors is an integer number (72631).

2³⁶¹⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

361805 is a deficient number, since it is larger than the sum of its proper divisors (73981).

361805 is an frugal number, since it uses more digits than its factorization.

361805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543 (or 274 counting only the distinct ones).

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

The square root of 361805 is about 601.5022859474. The cubic root of 361805 is about 71.2565603891.

Multiplying 361805 by its product of nonzero digits (720), we get a square (260499600 = 16140²).

Adding to 361805 its reverse (508163), we get a palindrome (869968).

It can be divided in two parts, 36 and 1805, that multiplied together give a triangular number (64980 = T₃₆₀).

The spelling of 361805 in words is "three hundred sixty-one thousand, eight hundred five".