81040373441 has 4 divisors (see below), whose sum is σ = 81048219072. Its totient is φ = 81032527812.

The previous prime is 81040373437. The next prime is 81040373461. The reversal of 81040373441 is 14437304018.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81040373441 - 2² = 81040373437 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81040373461) 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, 3907301 + ... + 3927986.

It is an arithmetic number, because the mean of its divisors is an integer number (20262054768).

Almost surely, 2^81040373441 is an apocalyptic number.

It is an amenable number.

81040373441 is a deficient number, since it is larger than the sum of its proper divisors (7845631).

81040373441 is a wasteful number, since it uses less digits than its factorization.

81040373441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7845630.

The product of its (nonzero) digits is 32256, while the sum is 35.

Adding to 81040373441 its reverse (14437304018), we get a palindrome (95477677459).

The spelling of 81040373441 in words is "eighty-one billion, forty million, three hundred seventy-three thousand, four hundred forty-one".