165981189 has 16 divisors (see below), whose sum is σ = 241750080. Its totient is φ = 100460160.

The previous prime is 165981187. The next prime is 165981191. The reversal of 165981189 is 981189561.

It is an interprime number because it is at equal distance from previous prime (165981187) and next prime (165981191).

It is not a de Polignac number, because 165981189 - 2¹ = 165981187 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165981187) 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, 25347 + ... + 31215.

It is an arithmetic number, because the mean of its divisors is an integer number (15109380).

Almost surely, 2^165981189 is an apocalyptic number.

It is an amenable number.

165981189 is a deficient number, since it is larger than the sum of its proper divisors (75768891).

165981189 is a wasteful number, since it uses less digits than its factorization.

165981189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6740.

The product of its digits is 155520, while the sum is 48.

The square root of 165981189 is about 12883.3686976660. The cubic root of 165981189 is about 549.5657056450.

The spelling of 165981189 in words is "one hundred sixty-five million, nine hundred eighty-one thousand, one hundred eighty-nine".