81366223 has 2 divisors, whose sum is σ = 81366224. Its totient is φ = 81366222.

The previous prime is 81366217. The next prime is 81366239. The reversal of 81366223 is 32266318.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81366223 - 2¹⁷ = 81235151 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81366283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40683111 + 40683112.

It is an arithmetic number, because the mean of its divisors is an integer number (40683112).

Almost surely, 2^81366223 is an apocalyptic number.

81366223 is a deficient number, since it is larger than the sum of its proper divisors (1).

81366223 is an equidigital number, since it uses as much as digits as its factorization.

81366223 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 31.

The square root of 81366223 is about 9020.3227769299. The cubic root of 81366223 is about 433.3259710123.

The spelling of 81366223 in words is "eighty-one million, three hundred sixty-six thousand, two hundred twenty-three".