81540041 has 16 divisors (see below), whose sum is σ = 94893120. Its totient is φ = 69242880.

The previous prime is 81540031. The next prime is 81540079. The reversal of 81540041 is 14004518.

It is a cyclic number.

It is not a de Polignac number, because 81540041 - 2⁶ = 81539977 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81539989 and 81540016.

It is not an unprimeable number, because it can be changed into a prime (81540031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24425 + ... + 27561.

It is an arithmetic number, because the mean of its divisors is an integer number (5930820).

Almost surely, 2^81540041 is an apocalyptic number.

It is an amenable number.

81540041 is a deficient number, since it is larger than the sum of its proper divisors (13353079).

81540041 is a wasteful number, since it uses less digits than its factorization.

81540041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3304.

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 81540041 is about 9029.9524361981. The cubic root of 81540041 is about 433.6343146984.

Adding to 81540041 its reverse (14004518), we get a palindrome (95544559).

The spelling of 81540041 in words is "eighty-one million, five hundred forty thousand, forty-one".