181385502461 has 2 divisors, whose sum is σ = 181385502462. Its totient is φ = 181385502460.

The previous prime is 181385502421. The next prime is 181385502589. The reversal of 181385502461 is 164205583181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 113215425625 + 68170076836 = 336475^2 + 261094^2 .

It is a cyclic number.

It is not a de Polignac number, because 181385502461 - 2¹⁴ = 181385486077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (181385502421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90692751230 + 90692751231.

It is an arithmetic number, because the mean of its divisors is an integer number (90692751231).

Almost surely, 2^181385502461 is an apocalyptic number.

It is an amenable number.

181385502461 is a deficient number, since it is larger than the sum of its proper divisors (1).

181385502461 is an equidigital number, since it uses as much as digits as its factorization.

181385502461 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 230400, while the sum is 44.

The spelling of 181385502461 in words is "one hundred eighty-one billion, three hundred eighty-five million, five hundred two thousand, four hundred sixty-one".