168538813 has 4 divisors (see below), whose sum is σ = 168648480. Its totient is φ = 168429148.

The previous prime is 168538793. The next prime is 168538831. The reversal of 168538813 is 318835861.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 168538813 - 2²¹ = 166441661 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 168538813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168538883) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52495 + ... + 55612.

It is an arithmetic number, because the mean of its divisors is an integer number (42162120).

Almost surely, 2^168538813 is an apocalyptic number.

It is an amenable number.

168538813 is a deficient number, since it is larger than the sum of its proper divisors (109667).

168538813 is a wasteful number, since it uses less digits than its factorization.

168538813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109666.

The product of its digits is 138240, while the sum is 43.

The square root of 168538813 is about 12982.2499205646. The cubic root of 168538813 is about 552.3741042496.

The spelling of 168538813 in words is "one hundred sixty-eight million, five hundred thirty-eight thousand, eight hundred thirteen".