81004841 has 4 divisors (see below), whose sum is σ = 81721812. Its totient is φ = 80287872.

The previous prime is 81004837. The next prime is 81004867. The reversal of 81004841 is 14840018.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 14840018 = 2 ⋅7420009.

It can be written as a sum of positive squares in 2 ways, for example, as 3916441 + 77088400 = 1979^2 + 8780^2 .

It is a cyclic number.

It is not a de Polignac number, because 81004841 - 2² = 81004837 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 81004841.

It is not an unprimeable number, because it can be changed into a prime (81004141) 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, 358316 + ... + 358541.

It is an arithmetic number, because the mean of its divisors is an integer number (20430453).

Almost surely, 2^81004841 is an apocalyptic number.

It is an amenable number.

81004841 is a deficient number, since it is larger than the sum of its proper divisors (716971).

81004841 is a wasteful number, since it uses less digits than its factorization.

81004841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716970.

The product of its (nonzero) digits is 1024, while the sum is 26.

The square root of 81004841 is about 9000.2689404262. The cubic root of 81004841 is about 432.6834905874.

Adding to 81004841 its reverse (14840018), we get a palindrome (95844859).

The spelling of 81004841 in words is "eighty-one million, four thousand, eight hundred forty-one".