168722987121 has 60 divisors (see below), whose sum is σ = 278900895196. Its totient is φ = 100974781440.

The previous prime is 168722987077. The next prime is 168722987141. The reversal of 168722987121 is 121789227861.

168722987121 is a `hidden beast` number, since 168 + 72 + 298 + 7 + 121 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 1364268096 + 167358719025 = 36936^2 + 409095^2 .

It is not a de Polignac number, because 168722987121 - 2¹³ = 168722978929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (168722987141) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 81076801 + ... + 81078881.

Almost surely, 2^168722987121 is an apocalyptic number.

It is an amenable number.

168722987121 is a deficient number, since it is larger than the sum of its proper divisors (110177908075).

168722987121 is an frugal number, since it uses more digits than its factorization.

168722987121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4224 (or 2134 counting only the distinct ones).

The product of its digits is 1354752, while the sum is 54.

The spelling of 168722987121 in words is "one hundred sixty-eight billion, seven hundred twenty-two million, nine hundred eighty-seven thousand, one hundred twenty-one".