81373223 has 2 divisors, whose sum is σ = 81373224. Its totient is φ = 81373222.

The previous prime is 81373211. The next prime is 81373247. The reversal of 81373223 is 32237318.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81373223 - 2¹⁰ = 81372199 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81373423) 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, 40686611 + 40686612.

It is an arithmetic number, because the mean of its divisors is an integer number (40686612).

Almost surely, 2^81373223 is an apocalyptic number.

81373223 is a deficient number, since it is larger than the sum of its proper divisors (1).

81373223 is an equidigital number, since it uses as much as digits as its factorization.

81373223 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 29.

The square root of 81373223 is about 9020.7107813076. The cubic root of 81373223 is about 433.3383971137.

The spelling of 81373223 in words is "eighty-one million, three hundred seventy-three thousand, two hundred twenty-three".