81266611 has 2 divisors, whose sum is σ = 81266612. Its totient is φ = 81266610.

The previous prime is 81266609. The next prime is 81266617. The reversal of 81266611 is 11666218.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81266611 - 2¹ = 81266609 is a prime.

Together with 81266609, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (81266617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40633305 + 40633306.

It is an arithmetic number, because the mean of its divisors is an integer number (40633306).

Almost surely, 2^81266611 is an apocalyptic number.

81266611 is a deficient number, since it is larger than the sum of its proper divisors (1).

81266611 is an equidigital number, since it uses as much as digits as its factorization.

81266611 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3456, while the sum is 31.

The square root of 81266611 is about 9014.7995540666. The cubic root of 81266611 is about 433.1490667572.

The spelling of 81266611 in words is "eighty-one million, two hundred sixty-six thousand, six hundred eleven".