81108361 has 2 divisors, whose sum is σ = 81108362. Its totient is φ = 81108360.

The previous prime is 81108289. The next prime is 81108383. The reversal of 81108361 is 16380118.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79762761 + 1345600 = 8931^2 + 1160^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81108361 is a prime.

It is not a weakly prime, because it can be changed into another prime (81108161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40554180 + 40554181.

It is an arithmetic number, because the mean of its divisors is an integer number (40554181).

Almost surely, 2^81108361 is an apocalyptic number.

It is an amenable number.

81108361 is a deficient number, since it is larger than the sum of its proper divisors (1).

81108361 is an equidigital number, since it uses as much as digits as its factorization.

81108361 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 81108361 is about 9006.0180435085. The cubic root of 81108361 is about 432.8677278402.

Adding to 81108361 its reverse (16380118), we get a palindrome (97488479).

It can be divided in two parts, 8110 and 8361, that added together give a triangular number (16471 = T₁₈₁).

The spelling of 81108361 in words is "eighty-one million, one hundred eight thousand, three hundred sixty-one".