81716557439440 has 160 divisors (see below), whose sum is σ = 241341173104896. Its totient is φ = 24989527879680.

The previous prime is 81716557439417. The next prime is 81716557439459. The reversal of 81716557439440 is 4493475561718.

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, 124821397 + ... + 125474356.

Almost surely, 2^{81716557439440} is an apocalyptic number.

81716557439440 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81716557439440 is an abundant number, since it is smaller than the sum of its proper divisors (159624615665456).

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

81716557439440 is a wasteful number, since it uses less digits than its factorization.

81716557439440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250295837 (or 250295831 counting only the distinct ones).

The product of its (nonzero) digits is 101606400, while the sum is 64.

The spelling of 81716557439440 in words is "eighty-one trillion, seven hundred sixteen billion, five hundred fifty-seven million, four hundred thirty-nine thousand, four hundred forty".