81287065760 has 48 divisors (see below), whose sum is σ = 196724628072. Its totient is φ = 31721779200.

The previous prime is 81287065757. The next prime is 81287065817. The reversal of 81287065760 is 6756078218.

It can be written as a sum of positive squares in 4 ways, for example, as 57463760656 + 23823305104 = 239716^2 + 154348^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81287065699 and 81287065708.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6189101 + ... + 6202220.

Almost surely, 2^81287065760 is an apocalyptic number.

81287065760 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81287065760 is an abundant number, since it is smaller than the sum of its proper divisors (115437562312).

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

81287065760 is a wasteful number, since it uses less digits than its factorization.

81287065760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12391377 (or 12391369 counting only the distinct ones).

The product of its (nonzero) digits is 1128960, while the sum is 50.

The spelling of 81287065760 in words is "eighty-one billion, two hundred eighty-seven million, sixty-five thousand, seven hundred sixty".