181816519361 has 4 divisors (see below), whose sum is σ = 181818268500. Its totient is φ = 181814770224.

The previous prime is 181816519351. The next prime is 181816519397. The reversal of 181816519361 is 163915618181.

It is a happy number.

181816519361 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 107211059761 + 74605459600 = 327431^2 + 273140^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-181816519361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181816519301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 708086 + ... + 930063.

It is an arithmetic number, because the mean of its divisors is an integer number (45454567125).

Almost surely, 2^181816519361 is an apocalyptic number.

It is an amenable number.

181816519361 is a deficient number, since it is larger than the sum of its proper divisors (1749139).

181816519361 is a wasteful number, since it uses less digits than its factorization.

181816519361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1749138.

The product of its digits is 311040, while the sum is 50.

The spelling of 181816519361 in words is "one hundred eighty-one billion, eight hundred sixteen million, five hundred nineteen thousand, three hundred sixty-one".