81475027440440 has 128 divisors (see below), whose sum is σ = 184293579456000. Its totient is φ = 32417279743488.

The previous prime is 81475027440421. The next prime is 81475027440451. The reversal of 81475027440440 is 4404472057418.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11617710374 + ... + 11617717386.

It is an arithmetic number, because the mean of its divisors is an integer number (1439793589500).

Almost surely, 2^{81475027440440} is an apocalyptic number.

It is an amenable number.

81475027440440 is an abundant number, since it is smaller than the sum of its proper divisors (102818552015560).

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

81475027440440 is a wasteful number, since it uses less digits than its factorization.

81475027440440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9309 (or 9305 counting only the distinct ones).

The product of its (nonzero) digits is 4014080, while the sum is 50.

Adding to 81475027440440 its reverse (4404472057418), we get a palindrome (85879499497858).

The spelling of 81475027440440 in words is "eighty-one trillion, four hundred seventy-five billion, twenty-seven million, four hundred forty thousand, four hundred forty".