109666 has 4 divisors (see below), whose sum is σ = 164502. Its totient is φ = 54832.

The previous prime is 109663. The next prime is 109673. The reversal of 109666 is 666901.

It is a happy number.

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., 93025 + 16641 = 305^2 + 129^2 .

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (109661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27415 + ... + 27418.

2¹⁰⁹⁶⁶⁶ is an apocalyptic number.

109666 is a deficient number, since it is larger than the sum of its proper divisors (54836).

109666 is an equidigital number, since it uses as much as digits as its factorization.

109666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54835.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 109666 is about 331.1585722883. The cubic root of 109666 is about 47.8656544281.

The spelling of 109666 in words is "one hundred nine thousand, six hundred sixty-six".