101666 has 4 divisors (see below), whose sum is σ = 152502. Its totient is φ = 50832.

The previous prime is 101663. The next prime is 101681. The reversal of 101666 is 666101.

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

It can be written as a sum of positive squares in only one way, i.e., 87025 + 14641 = 295^2 + 121^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 101666.

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 as a sum of consecutive naturals, namely, 25415 + ... + 25418.

2¹⁰¹⁶⁶⁶ is an apocalyptic number.

101666 is a deficient number, since it is larger than the sum of its proper divisors (50836).

101666 is an equidigital number, since it uses as much as digits as its factorization.

101666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50835.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 101666 is about 318.8510624100. The cubic root of 101666 is about 46.6722328961.

Adding to 101666 its reverse (666101), we get a palindrome (767767).

It can be divided in two parts, 101 and 666, that added together give a palindrome (767).

The spelling of 101666 in words is "one hundred one thousand, six hundred sixty-six".