81449871288 has 16 divisors (see below), whose sum is σ = 203624678280. Its totient is φ = 27149957088.

The previous prime is 81449871211. The next prime is 81449871299. The reversal of 81449871288 is 88217894418.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1696872295 + ... + 1696872342.

Almost surely, 2^81449871288 is an apocalyptic number.

It is an amenable number.

81449871288 is an abundant number, since it is smaller than the sum of its proper divisors (122174806992).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81449871288 is a wasteful number, since it uses less digits than its factorization.

81449871288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3393744646 (or 3393744642 counting only the distinct ones).

The product of its digits is 8257536, while the sum is 60.

The spelling of 81449871288 in words is "eighty-one billion, four hundred forty-nine million, eight hundred seventy-one thousand, two hundred eighty-eight".