18965 has 4 divisors (see below), whose sum is σ = 22764. Its totient is φ = 15168.

The previous prime is 18959. The next prime is 18973. The reversal of 18965 is 56981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56981 = 19 ⋅2999.

It can be written as a sum of positive squares in 2 ways, for example, as 5041 + 13924 = 71^2 + 118^2 .

It is a cyclic number.

It is not a de Polignac number, because 18965 - 2¹² = 14869 is a prime.

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

It is a Duffinian number.

It is a plaindrome in base 6.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1892 + ... + 1901.

It is an arithmetic number, because the mean of its divisors is an integer number (5691).

2¹⁸⁹⁶⁵ is an apocalyptic number.

It is an amenable number.

18965 is a deficient number, since it is larger than the sum of its proper divisors (3799).

18965 is an equidigital number, since it uses as much as digits as its factorization.

18965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3798.

The product of its digits is 2160, while the sum is 29.

The square root of 18965 is about 137.7134706556. The cubic root of 18965 is about 26.6676214936.

The spelling of 18965 in words is "eighteen thousand, nine hundred sixty-five".