155666 has 8 divisors (see below), whose sum is σ = 266880. Its totient is φ = 66708.

The previous prime is 155663. The next prime is 155671. The reversal of 155666 is 666551.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a plaindrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (155663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5546 + ... + 5573.

It is an arithmetic number, because the mean of its divisors is an integer number (33360).

2¹⁵⁵⁶⁶⁶ is an apocalyptic number.

155666 is a deficient number, since it is larger than the sum of its proper divisors (111214).

155666 is a wasteful number, since it uses less digits than its factorization.

155666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11128.

The product of its digits is 5400, while the sum is 29.

The square root of 155666 is about 394.5453079179. The cubic root of 155666 is about 53.7936800157.

The spelling of 155666 in words is "one hundred fifty-five thousand, six hundred sixty-six".