81684708084 has 144 divisors (see below), whose sum is σ = 237369315456. Its totient is φ = 23201280000.

The previous prime is 81684708037. The next prime is 81684708143. The reversal of 81684708084 is 48080748618.

81684708084 is a `hidden beast` number, since 8 + 16 + 8 + 470 + 80 + 84 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 81684708084.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 48133924 + ... + 48135620.

It is an arithmetic number, because the mean of its divisors is an integer number (1648398024).

Almost surely, 2^81684708084 is an apocalyptic number.

81684708084 is a gapful number since it is divisible by the number (84) 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 81684708084, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118684657728).

81684708084 is an abundant number, since it is smaller than the sum of its proper divisors (155684607372).

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

81684708084 is a wasteful number, since it uses less digits than its factorization.

81684708084 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2726 (or 2721 counting only the distinct ones).

The product of its (nonzero) digits is 2752512, while the sum is 54.

The spelling of 81684708084 in words is "eighty-one billion, six hundred eighty-four million, seven hundred eight thousand, eighty-four".