81072541 has 16 divisors (see below), whose sum is σ = 94445568. Its totient is φ = 69347520.

The previous prime is 81072529. The next prime is 81072547. The reversal of 81072541 is 14527018.

It is not a de Polignac number, because 81072541 - 2⁹ = 81072029 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81072547) 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 15 ways as a sum of consecutive naturals, for example, 20836 + ... + 24418.

It is an arithmetic number, because the mean of its divisors is an integer number (5902848).

Almost surely, 2^81072541 is an apocalyptic number.

It is an amenable number.

81072541 is a deficient number, since it is larger than the sum of its proper divisors (13373027).

81072541 is a wasteful number, since it uses less digits than its factorization.

81072541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3633 (or 3611 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 81072541 is about 9004.0291536623. The cubic root of 81072541 is about 432.8039957953.

Adding to 81072541 its reverse (14527018), we get a palindrome (95599559).

It can be divided in two parts, 8107 and 2541, that added together give a cube (10648 = 22³).

The spelling of 81072541 in words is "eighty-one million, seventy-two thousand, five hundred forty-one".