81548328959 has 4 divisors (see below), whose sum is σ = 86345289504. Its totient is φ = 76751368416.

The previous prime is 81548328907. The next prime is 81548328989. The reversal of 81548328959 is 95982384518.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81548328959 - 2⁸ = 81548328703 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81548328989) 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, 2398480247 + ... + 2398480280.

It is an arithmetic number, because the mean of its divisors is an integer number (21586322376).

Almost surely, 2^81548328959 is an apocalyptic number.

81548328959 is a deficient number, since it is larger than the sum of its proper divisors (4796960545).

81548328959 is a wasteful number, since it uses less digits than its factorization.

81548328959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4796960544.

The product of its digits is 24883200, while the sum is 62.

The spelling of 81548328959 in words is "eighty-one billion, five hundred forty-eight million, three hundred twenty-eight thousand, nine hundred fifty-nine".