101661 has 16 divisors (see below), whose sum is σ = 159744. Its totient is φ = 56304.

The previous prime is 101653. The next prime is 101663. The reversal of 101661 is 166101.

It is not a de Polignac number, because 101661 - 2³ = 101653 is a prime.

It is a Curzon number.

101661 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 101661.

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 101661.

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

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 936 + ... + 1038.

It is an arithmetic number, because the mean of its divisors is an integer number (9984).

2¹⁰¹⁶⁶¹ is an apocalyptic number.

It is an amenable number.

101661 is a deficient number, since it is larger than the sum of its proper divisors (58083).

101661 is a wasteful number, since it uses less digits than its factorization.

101661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 101661 is about 318.8432216623. The cubic root of 101661 is about 46.6714677600.

Adding to 101661 its reverse (166101), we get a palindrome (267762).

The spelling of 101661 in words is "one hundred one thousand, six hundred sixty-one".