81715886280 has 384 divisors, whose sum is σ = 338287622400. Its totient is φ = 16653828096.

The previous prime is 81715886183. The next prime is 81715886293. The reversal of 81715886280 is 8268851718.

81715886280 is a `hidden beast` number, since 8 + 1 + 7 + 1 + 5 + 8 + 8 + 628 + 0 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 763764 + ... + 864156.

It is an arithmetic number, because the mean of its divisors is an integer number (880957350).

Almost surely, 2^81715886280 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81715886280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169143811200).

81715886280 is an abundant number, since it is smaller than the sum of its proper divisors (256571736120).

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

81715886280 is a wasteful number, since it uses less digits than its factorization.

81715886280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100453 (or 100446 counting only the distinct ones).

The product of its (nonzero) digits is 1720320, while the sum is 54.

The spelling of 81715886280 in words is "eighty-one billion, seven hundred fifteen million, eight hundred eighty-six thousand, two hundred eighty".