81436041 has 12 divisors (see below), whose sum is σ = 117967668. Its totient is φ = 54134784.

The previous prime is 81436013. The next prime is 81436051. The reversal of 81436041 is 14063418.

It can be written as a sum of positive squares in 2 ways, for example, as 30969225 + 50466816 = 5565^2 + 7104^2 .

It is a de Polignac number, because none of the positive numbers 2^k-81436041 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81435996 and 81436014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81436051) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9640 + ... + 15993.

It is an arithmetic number, because the mean of its divisors is an integer number (9830639).

Almost surely, 2^81436041 is an apocalyptic number.

It is an amenable number.

81436041 is a deficient number, since it is larger than the sum of its proper divisors (36531627).

81436041 is a wasteful number, since it uses less digits than its factorization.

81436041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25992 (or 25989 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 81436041 is about 9024.1919859897. The cubic root of 81436041 is about 433.4498770686.

Adding to 81436041 its reverse (14063418), we get a palindrome (95499459).

The spelling of 81436041 in words is "eighty-one million, four hundred thirty-six thousand, forty-one".