81008541 has 18 divisors (see below), whose sum is σ = 118188798. Its totient is φ = 53466480.

The previous prime is 81008509. The next prime is 81008569. The reversal of 81008541 is 14580018.

It can be written as a sum of positive squares in only one way, i.e., 44756100 + 36252441 = 6690^2 + 6021^2 .

It is not a de Polignac number, because 81008541 - 2⁵ = 81008509 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81008591) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 363156 + ... + 363378.

Almost surely, 2^81008541 is an apocalyptic number.

It is an amenable number.

81008541 is a deficient number, since it is larger than the sum of its proper divisors (37180257).

81008541 is a wasteful number, since it uses less digits than its factorization.

81008541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 633 (or 407 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 81008541 is about 9000.4744874923. The cubic root of 81008541 is about 432.6900782782.

Adding to 81008541 its reverse (14580018), we get a palindrome (95588559).

It can be divided in two parts, 8100 and 8541, that added together give a square (16641 = 129²).

The spelling of 81008541 in words is "eighty-one million, eight thousand, five hundred forty-one".