81594319541 has 8 divisors (see below), whose sum is σ = 93436043904. Its totient is φ = 69798943440.

The previous prime is 81594319529. The next prime is 81594319561. The reversal of 81594319541 is 14591349518.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81594319541 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81594319541.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81594319561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11583290 + ... + 11590331.

It is an arithmetic number, because the mean of its divisors is an integer number (11679505488).

Almost surely, 2^81594319541 is an apocalyptic number.

It is an amenable number.

81594319541 is a deficient number, since it is larger than the sum of its proper divisors (11841724363).

81594319541 is a wasteful number, since it uses less digits than its factorization.

81594319541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23174131.

The product of its digits is 777600, while the sum is 50.

The spelling of 81594319541 in words is "eighty-one billion, five hundred ninety-four million, three hundred nineteen thousand, five hundred forty-one".