81818227 has 2 divisors, whose sum is σ = 81818228. Its totient is φ = 81818226.

The previous prime is 81818197. The next prime is 81818279. The reversal of 81818227 is 72281818.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81818227 is a prime.

It is not a weakly prime, because it can be changed into another prime (81818927) 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, 40909113 + 40909114.

It is an arithmetic number, because the mean of its divisors is an integer number (40909114).

Almost surely, 2^81818227 is an apocalyptic number.

81818227 is a deficient number, since it is larger than the sum of its proper divisors (1).

81818227 is an equidigital number, since it uses as much as digits as its factorization.

81818227 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14336, while the sum is 37.

The square root of 81818227 is about 9045.3428348515. The cubic root of 81818227 is about 434.1268909831.

The spelling of 81818227 in words is "eighty-one million, eight hundred eighteen thousand, two hundred twenty-seven".