101665 has 4 divisors (see below), whose sum is σ = 122004. Its totient is φ = 81328.

The previous prime is 101663. The next prime is 101681. The reversal of 101665 is 566101.

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

It can be written as a sum of positive squares in 2 ways, for example, as 73441 + 28224 = 271^2 + 168^2 .

It is a cyclic number.

It is not a de Polignac number, because 101665 - 2¹ = 101663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (101663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10162 + ... + 10171.

It is an arithmetic number, because the mean of its divisors is an integer number (30501).

2¹⁰¹⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

101665 is a deficient number, since it is larger than the sum of its proper divisors (20339).

101665 is an equidigital number, since it uses as much as digits as its factorization.

101665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20338.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 101665 is about 318.8494942759. The cubic root of 101665 is about 46.6720798709.

Adding to 101665 its reverse (566101), we get a palindrome (667766).

It can be divided in two parts, 1016 and 65, that added together give a triangular number (1081 = T₄₆).

The spelling of 101665 in words is "one hundred one thousand, six hundred sixty-five".