81332541 has 12 divisors (see below), whose sum is σ = 118521468. Its totient is φ = 53741184.

The previous prime is 81332473. The next prime is 81332543. The reversal of 81332541 is 14523318.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 13616100 + 67716441 = 3690^2 + 8229^2 .

It is not a de Polignac number, because 81332541 - 2¹¹ = 81330493 is a prime.

It is a super-2 number, since 2×81332541² = 13229964451033362, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81332543) 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 11 ways as a sum of consecutive naturals, for example, 38970 + ... + 41003.

It is an arithmetic number, because the mean of its divisors is an integer number (9876789).

Almost surely, 2^81332541 is an apocalyptic number.

It is an amenable number.

81332541 is a deficient number, since it is larger than the sum of its proper divisors (37188927).

81332541 is a wasteful number, since it uses less digits than its factorization.

81332541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80092 (or 80089 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 81332541 is about 9018.4555773148. The cubic root of 81332541 is about 433.2661701957.

Adding to 81332541 its reverse (14523318), we get a palindrome (95855859).

The spelling of 81332541 in words is "eighty-one million, three hundred thirty-two thousand, five hundred forty-one".