168501219121 has 3 divisors (see below), whose sum is σ = 168501629611. Its totient is φ = 168500808632.

The previous prime is 168501219101. The next prime is 168501219151. The reversal of 168501219121 is 121912105861.

It is a happy number.

The square root of 168501219121 is 410489.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 84354812721 + 84146406400 = 290439^2 + 290080^2 .

It is not a de Polignac number, because 168501219121 - 2²⁵ = 168467664689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (168501219101) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 205245 + ... + 615733.

Almost surely, 2^168501219121 is an apocalyptic number.

168501219121 is the 410489-th square number.

168501219121 is the 205245-th centered octagonal number.

It is an amenable number.

168501219121 is a deficient number, since it is larger than the sum of its proper divisors (410490).

168501219121 is an frugal number, since it uses more digits than its factorization.

168501219121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820978 (or 410489 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 37.

The spelling of 168501219121 in words is "one hundred sixty-eight billion, five hundred one million, two hundred nineteen thousand, one hundred twenty-one".