168531389 has 8 divisors (see below), whose sum is σ = 183367800. Its totient is φ = 153962496.

The previous prime is 168531359. The next prime is 168531401. The reversal of 168531389 is 983135861.

It can be written as a sum of positive squares in 4 ways, for example, as 7672900 + 160858489 = 2770^2 + 12683^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 168531389 - 2⁸ = 168531133 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168531329) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 65564 + ... + 68085.

It is an arithmetic number, because the mean of its divisors is an integer number (22920975).

Almost surely, 2^168531389 is an apocalyptic number.

It is an amenable number.

168531389 is a deficient number, since it is larger than the sum of its proper divisors (14836411).

168531389 is a wasteful number, since it uses less digits than its factorization.

168531389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133759.

The product of its digits is 155520, while the sum is 44.

The square root of 168531389 is about 12981.9639885497. The cubic root of 168531389 is about 552.3659935846.

The spelling of 168531389 in words is "one hundred sixty-eight million, five hundred thirty-one thousand, three hundred eighty-nine".