181966 has 8 divisors (see below), whose sum is σ = 280440. Its totient is φ = 88488.

The previous prime is 181957. The next prime is 181967. The reversal of 181966 is 669181.

It is a happy number.

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

It is a super-2 number, since 2×181966² = 66223250312, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181967) by changing a digit.

181966 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1156 + ... + 1303.

It is an arithmetic number, because the mean of its divisors is an integer number (35055).

2¹⁸¹⁹⁶⁶ is an apocalyptic number.

181966 is a deficient number, since it is larger than the sum of its proper divisors (98474).

181966 is a wasteful number, since it uses less digits than its factorization.

181966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2498.

The product of its digits is 2592, while the sum is 31.

The square root of 181966 is about 426.5747296782. The cubic root of 181966 is about 56.6669819283. Note that the first 3 decimals are identical.

The spelling of 181966 in words is "one hundred eighty-one thousand, nine hundred sixty-six".