168721517372 has 24 divisors (see below), whose sum is σ = 297215414496. Its totient is φ = 83804502528.

The previous prime is 168721517309. The next prime is 168721517387. The reversal of 168721517372 is 273715127861.

It is a Smith number, since the sum of its digits (50) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 168721517372.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 194513 + ... + 612599.

It is an arithmetic number, because the mean of its divisors is an integer number (12383975604).

Almost surely, 2^168721517372 is an apocalyptic number.

It is an amenable number.

168721517372 is a deficient number, since it is larger than the sum of its proper divisors (128493897124).

168721517372 is a wasteful number, since it uses less digits than its factorization.

168721517372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 418757 (or 418755 counting only the distinct ones).

The product of its digits is 987840, while the sum is 50.

The spelling of 168721517372 in words is "one hundred sixty-eight billion, seven hundred twenty-one million, five hundred seventeen thousand, three hundred seventy-two".