181516566325 has 12 divisors (see below), whose sum is σ = 230570312868. Its totient is φ = 141671465600.

The previous prime is 181516566323. The next prime is 181516566331. The reversal of 181516566325 is 523665615181.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 54888055524 + 126628510801 = 234282^2 + 355849^2 .

It is not a de Polignac number, because 181516566325 - 2¹ = 181516566323 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181516566323) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 88543642 + ... + 88545691.

It is an arithmetic number, because the mean of its divisors is an integer number (19214192739).

Almost surely, 2^181516566325 is an apocalyptic number.

It is an amenable number.

181516566325 is a deficient number, since it is larger than the sum of its proper divisors (49053746543).

181516566325 is a wasteful number, since it uses less digits than its factorization.

181516566325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177089384 (or 177089379 counting only the distinct ones).

The product of its digits is 1296000, while the sum is 49.

The spelling of 181516566325 in words is "one hundred eighty-one billion, five hundred sixteen million, five hundred sixty-six thousand, three hundred twenty-five".