81329147 has 2 divisors, whose sum is σ = 81329148. Its totient is φ = 81329146.

The previous prime is 81329141. The next prime is 81329197. The reversal of 81329147 is 74192318.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81329147 - 2¹⁰ = 81328123 is a prime.

It is a super-2 number, since 2×81329147² = 13228860303495218, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81329141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40664573 + 40664574.

It is an arithmetic number, because the mean of its divisors is an integer number (40664574).

Almost surely, 2^81329147 is an apocalyptic number.

81329147 is a deficient number, since it is larger than the sum of its proper divisors (1).

81329147 is an equidigital number, since it uses as much as digits as its factorization.

81329147 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 35.

The square root of 81329147 is about 9018.2674056606. The cubic root of 81329147 is about 433.2601433917.

The spelling of 81329147 in words is "eighty-one million, three hundred twenty-nine thousand, one hundred forty-seven".