81718255639040 has 240 divisors, whose sum is σ = 204917940412416. Its totient is φ = 31251389030400.

The previous prime is 81718255638991. The next prime is 81718255639061. The reversal of 81718255639040 is 4093655281718.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3129635585 + ... + 3129661695.

It is a 1-persistent number, because it is pandigital, but 2⋅81718255639040 = 163436511278080 is not.

Almost surely, 2^{81718255639040} is an apocalyptic number.

81718255639040 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81718255639040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102458970206208).

81718255639040 is an abundant number, since it is smaller than the sum of its proper divisors (123199684773376).

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

81718255639040 is a wasteful number, since it uses less digits than its factorization.

81718255639040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28491 (or 28452 counting only the distinct ones).

The product of its (nonzero) digits is 14515200, while the sum is 59.

The spelling of 81718255639040 in words is "eighty-one trillion, seven hundred eighteen billion, two hundred fifty-five million, six hundred thirty-nine thousand, forty".