81459541 has 4 divisors (see below), whose sum is σ = 81663084. Its totient is φ = 81256000.

The previous prime is 81459527. The next prime is 81459551. The reversal of 81459541 is 14595418.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 78411025 + 3048516 = 8855^2 + 1746^2 .

It is a cyclic number.

It is not a de Polignac number, because 81459541 - 2¹⁵ = 81426773 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81459541.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81459551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101170 + ... + 101971.

It is an arithmetic number, because the mean of its divisors is an integer number (20415771).

Almost surely, 2^81459541 is an apocalyptic number.

It is an amenable number.

81459541 is a deficient number, since it is larger than the sum of its proper divisors (203543).

81459541 is a wasteful number, since it uses less digits than its factorization.

81459541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203542.

The product of its digits is 28800, while the sum is 37.

The square root of 81459541 is about 9025.4939477017. The cubic root of 81459541 is about 433.4915666053.

The spelling of 81459541 in words is "eighty-one million, four hundred fifty-nine thousand, five hundred forty-one".