168138549 has 24 divisors (see below), whose sum is σ = 251940000. Its totient is φ = 107926560.

The previous prime is 168138547. The next prime is 168138563. The reversal of 168138549 is 945831861.

It is not a de Polignac number, because 168138549 - 2¹ = 168138547 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168138547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 129594 + ... + 130884.

It is an arithmetic number, because the mean of its divisors is an integer number (10497500).

Almost surely, 2^168138549 is an apocalyptic number.

It is an amenable number.

168138549 is a deficient number, since it is larger than the sum of its proper divisors (83801451).

168138549 is a wasteful number, since it uses less digits than its factorization.

168138549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1825 (or 1822 counting only the distinct ones).

The product of its digits is 207360, while the sum is 45.

The square root of 168138549 is about 12966.8249390512. The cubic root of 168138549 is about 551.9364785916.

The spelling of 168138549 in words is "one hundred sixty-eight million, one hundred thirty-eight thousand, five hundred forty-nine".