365861 has 4 divisors (see below), whose sum is σ = 381792. Its totient is φ = 349932.

The previous prime is 365851. The next prime is 365903. The reversal of 365861 is 168563.

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, and also an emirpimes, since its reverse is a distinct semiprime: 168563 = 59 ⋅2857.

It is a cyclic number.

It is not a de Polignac number, because 365861 - 2⁶ = 365797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (365851) 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, 7931 + ... + 7976.

It is an arithmetic number, because the mean of its divisors is an integer number (95448).

2³⁶⁵⁸⁶¹ is an apocalyptic number.

It is an amenable number.

365861 is a deficient number, since it is larger than the sum of its proper divisors (15931).

365861 is a wasteful number, since it uses less digits than its factorization.

365861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15930.

The product of its digits is 4320, while the sum is 29.

The square root of 365861 is about 604.8644476244. The cubic root of 365861 is about 71.5218444347.

The spelling of 365861 in words is "three hundred sixty-five thousand, eight hundred sixty-one".