181612856113 has 4 divisors (see below), whose sum is σ = 195583075828. Its totient is φ = 167642636400.

The previous prime is 181612856093. The next prime is 181612856141. The reversal of 181612856113 is 311658216181.

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 79483397184 + 102129458929 = 281928^2 + 319577^2 .

It is a cyclic number.

It is not a de Polignac number, because 181612856113 - 2²¹ = 181610758961 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 181612856113.

It is not an unprimeable number, because it can be changed into a prime (181612856153) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6985109838 + ... + 6985109863.

It is an arithmetic number, because the mean of its divisors is an integer number (48895768957).

Almost surely, 2^181612856113 is an apocalyptic number.

181612856113 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

181612856113 is a deficient number, since it is larger than the sum of its proper divisors (13970219715).

181612856113 is a wasteful number, since it uses less digits than its factorization.

181612856113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13970219714.

The product of its digits is 69120, while the sum is 43.

The spelling of 181612856113 in words is "one hundred eighty-one billion, six hundred twelve million, eight hundred fifty-six thousand, one hundred thirteen".