81529305 has 64 divisors (see below), whose sum is σ = 154828800. Its totient is φ = 36115200.

The previous prime is 81529303. The next prime is 81529313. The reversal of 81529305 is 50392518.

It is not a de Polignac number, because 81529305 - 2¹ = 81529303 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (81529303) 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 in 63 ways as a sum of consecutive naturals, for example, 409596 + ... + 409794.

It is an arithmetic number, because the mean of its divisors is an integer number (2419200).

Almost surely, 2^81529305 is an apocalyptic number.

It is an amenable number.

81529305 is a deficient number, since it is larger than the sum of its proper divisors (73299495).

81529305 is a wasteful number, since it uses less digits than its factorization.

81529305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 422.

The product of its (nonzero) digits is 10800, while the sum is 33.

The square root of 81529305 is about 9029.3579505965. The cubic root of 81529305 is about 433.6152823216.

The spelling of 81529305 in words is "eighty-one million, five hundred twenty-nine thousand, three hundred five".