81162841 has 4 divisors (see below), whose sum is σ = 81180900. Its totient is φ = 81144784.

The previous prime is 81162839. The next prime is 81162847. The reversal of 81162841 is 14826118.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 53231616 + 27931225 = 7296^2 + 5285^2 .

It is a cyclic number.

It is not a de Polignac number, because 81162841 - 2¹ = 81162839 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81162847) 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, 3615 + ... + 13243.

It is an arithmetic number, because the mean of its divisors is an integer number (20295225).

Almost surely, 2^81162841 is an apocalyptic number.

It is an amenable number.

81162841 is a deficient number, since it is larger than the sum of its proper divisors (18059).

81162841 is an equidigital number, since it uses as much as digits as its factorization.

81162841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18058.

The product of its digits is 3072, while the sum is 31.

The square root of 81162841 is about 9009.0421799434. The cubic root of 81162841 is about 432.9646243681.

Adding to 81162841 its reverse (14826118), we get a palindrome (95988959).

The spelling of 81162841 in words is "eighty-one million, one hundred sixty-two thousand, eight hundred forty-one".