81132771 has 16 divisors (see below), whose sum is σ = 111041280. Its totient is φ = 52671840.

The previous prime is 81132769. The next prime is 81132803. The reversal of 81132771 is 17723118.

It is not a de Polignac number, because 81132771 - 2¹ = 81132769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81133771) 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 in 15 ways as a sum of consecutive naturals, for example, 20266 + ... + 23936.

It is an arithmetic number, because the mean of its divisors is an integer number (6940080).

Almost surely, 2^81132771 is an apocalyptic number.

81132771 is a deficient number, since it is larger than the sum of its proper divisors (29908509).

81132771 is a wasteful number, since it uses less digits than its factorization.

81132771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3866.

The product of its digits is 2352, while the sum is 30.

The square root of 81132771 is about 9007.3731464839. The cubic root of 81132771 is about 432.9111481128.

Adding to 81132771 its reverse (17723118), we get a palindrome (98855889).

The spelling of 81132771 in words is "eighty-one million, one hundred thirty-two thousand, seven hundred seventy-one".