81366611 has 2 divisors, whose sum is σ = 81366612. Its totient is φ = 81366610.

The previous prime is 81366587. The next prime is 81366613. The reversal of 81366611 is 11666318.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81366611 - 2²² = 77172307 is a prime.

Together with 81366613, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81366613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40683305 + 40683306.

It is an arithmetic number, because the mean of its divisors is an integer number (40683306).

Almost surely, 2^81366611 is an apocalyptic number.

81366611 is a deficient number, since it is larger than the sum of its proper divisors (1).

81366611 is an equidigital number, since it uses as much as digits as its factorization.

81366611 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 32.

The square root of 81366611 is about 9020.3442838952. The cubic root of 81366611 is about 433.3266597920.

The spelling of 81366611 in words is "eighty-one million, three hundred sixty-six thousand, six hundred eleven".