81593725497 has 8 divisors (see below), whose sum is σ = 109013207520. Its totient is φ = 54285030240.

The previous prime is 81593725459. The next prime is 81593725513. The reversal of 81593725497 is 79452739518.

It is a happy number.

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

It is not a de Polignac number, because 81593725497 - 2¹⁰ = 81593724473 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81593725497.

It is not an unprimeable number, because it can be changed into a prime (81593725427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27694972 + ... + 27697917.

It is an arithmetic number, because the mean of its divisors is an integer number (13626650940).

Almost surely, 2^81593725497 is an apocalyptic number.

It is an amenable number.

81593725497 is a deficient number, since it is larger than the sum of its proper divisors (27419482023).

81593725497 is a wasteful number, since it uses less digits than its factorization.

81593725497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55393383.

The product of its digits is 19051200, while the sum is 60.

The spelling of 81593725497 in words is "eighty-one billion, five hundred ninety-three million, seven hundred twenty-five thousand, four hundred ninety-seven".