165823989 has 16 divisors (see below), whose sum is σ = 224452800. Its totient is φ = 108884736.

The previous prime is 165823981. The next prime is 165823993. The reversal of 165823989 is 989328561.

It is a happy number.

It is not a de Polignac number, because 165823989 - 2³ = 165823981 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165823981) 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, 57117 + ... + 59949.

It is an arithmetic number, because the mean of its divisors is an integer number (14028300).

Almost surely, 2^165823989 is an apocalyptic number.

It is an amenable number.

165823989 is a deficient number, since it is larger than the sum of its proper divisors (58628811).

165823989 is a wasteful number, since it uses less digits than its factorization.

165823989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3124.

The product of its digits is 933120, while the sum is 51.

The square root of 165823989 is about 12877.2663636348. The cubic root of 165823989 is about 549.3921538155.

The spelling of 165823989 in words is "one hundred sixty-five million, eight hundred twenty-three thousand, nine hundred eighty-nine".