181965 has 16 divisors (see below), whose sum is σ = 332928. Its totient is φ = 83136.

The previous prime is 181957. The next prime is 181967. The reversal of 181965 is 569181.

It is a happy number.

It is not a de Polignac number, because 181965 - 2³ = 181957 is a prime.

It is a super-2 number, since 2×181965² = 66222522450, 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.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 762 + ... + 971.

It is an arithmetic number, because the mean of its divisors is an integer number (20808).

2¹⁸¹⁹⁶⁵ is an apocalyptic number.

181965 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

181965 is a deficient number, since it is larger than the sum of its proper divisors (150963).

181965 is a wasteful number, since it uses less digits than its factorization.

181965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1748.

The product of its digits is 2160, while the sum is 30.

The square root of 181965 is about 426.5735575490. The cubic root of 181965 is about 56.6668781230. Note that the first 3 decimals are identical.

The spelling of 181965 in words is "one hundred eighty-one thousand, nine hundred sixty-five".