189945 has 40 divisors (see below), whose sum is σ = 394944. Its totient is φ = 85536.

The previous prime is 189929. The next prime is 189947. The reversal of 189945 is 549981.

It is not a de Polignac number, because 189945 - 2⁴ = 189929 is a prime.

It is not an unprimeable number, because it can be changed into a prime (189947) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 2802 + ... + 2868.

2¹⁸⁹⁹⁴⁵ is an apocalyptic number.

189945 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

189945 is an abundant number, since it is smaller than the sum of its proper divisors (204999).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

189945 is an equidigital number, since it uses as much as digits as its factorization.

189945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91 (or 82 counting only the distinct ones).

The product of its digits is 12960, while the sum is 36.

The square root of 189945 is about 435.8268004609. The cubic root of 189945 is about 57.4834230727.

Adding to 189945 its sum of digits (36), we get a palindrome (189981).

The spelling of 189945 in words is "one hundred eighty-nine thousand, nine hundred forty-five".