81548328961 has 8 divisors (see below), whose sum is σ = 89307971424. Its totient is φ = 73846379520.

The previous prime is 81548328907. The next prime is 81548328989. The reversal of 81548328961 is 16982384518.

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 not a de Polignac number, because 81548328961 - 2²⁹ = 81011458049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81548328361) 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, 14420295 + ... + 14425948.

It is an arithmetic number, because the mean of its divisors is an integer number (11163496428).

Almost surely, 2^81548328961 is an apocalyptic number.

It is an amenable number.

81548328961 is a deficient number, since it is larger than the sum of its proper divisors (7759642463).

81548328961 is a wasteful number, since it uses less digits than its factorization.

81548328961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28846511.

The product of its digits is 3317760, while the sum is 55.

The spelling of 81548328961 in words is "eighty-one billion, five hundred forty-eight million, three hundred twenty-eight thousand, nine hundred sixty-one".