81329263 has 2 divisors, whose sum is σ = 81329264. Its totient is φ = 81329262.

The previous prime is 81329257. The next prime is 81329323. The reversal of 81329263 is 36292318.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81329263 is a prime.

It is a super-2 number, since 2×81329263² = 13228898040246338, which contains 22 as substring.

It is equal to p_4742575 and since 81329263 and 4742575 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81329233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40664631 + 40664632.

It is an arithmetic number, because the mean of its divisors is an integer number (40664632).

Almost surely, 2^81329263 is an apocalyptic number.

81329263 is a deficient number, since it is larger than the sum of its proper divisors (1).

81329263 is an equidigital number, since it uses as much as digits as its factorization.

81329263 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 34.

The square root of 81329263 is about 9018.2738370489. The cubic root of 81329263 is about 433.2603493784.

The spelling of 81329263 in words is "eighty-one million, three hundred twenty-nine thousand, two hundred sixty-three".