81367109 has 2 divisors, whose sum is σ = 81367110. Its totient is φ = 81367108.

The previous prime is 81367103. The next prime is 81367133. The reversal of 81367109 is 90176318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 73788100 + 7579009 = 8590^2 + 2753^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81367109 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81367103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40683554 + 40683555.

It is an arithmetic number, because the mean of its divisors is an integer number (40683555).

Almost surely, 2^81367109 is an apocalyptic number.

It is an amenable number.

81367109 is a deficient number, since it is larger than the sum of its proper divisors (1).

81367109 is an equidigital number, since it uses as much as digits as its factorization.

81367109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 35.

The square root of 81367109 is about 9020.3718881208. The cubic root of 81367109 is about 433.3275438411.

The spelling of 81367109 in words is "eighty-one million, three hundred sixty-seven thousand, one hundred nine".