12725722161 has 54 divisors (see below), whose sum is σ = 19560463650. Its totient is φ = 8278617312.

The previous prime is 12725722159. The next prime is 12725722193. The reversal of 12725722161 is 16122752721.

12725722161 is a `hidden beast` number, since 1 + 2 + 7 + 2 + 572 + 21 + 61 = 666.

It can be written as a sum of positive squares in only one way, i.e., 12422439936 + 303282225 = 111456^2 + 17415^2 .

It is not a de Polignac number, because 12725722161 - 2¹ = 12725722159 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12725722661) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 12130765 + ... + 12131813.

Almost surely, 2^12725722161 is an apocalyptic number.

It is an amenable number.

12725722161 is a deficient number, since it is larger than the sum of its proper divisors (6834741489).

12725722161 is an frugal number, since it uses more digits than its factorization.

12725722161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1159 (or 1095 counting only the distinct ones).

The product of its digits is 23520, while the sum is 36.

The spelling of 12725722161 in words is "twelve billion, seven hundred twenty-five million, seven hundred twenty-two thousand, one hundred sixty-one".