81439852968 has 96 divisors (see below), whose sum is σ = 228399350400. Its totient is φ = 26184412800.

The previous prime is 81439852889. The next prime is 81439852987. The reversal of 81439852968 is 86925893418.

81439852968 is a `hidden beast` number, since 8 + 1 + 43 + 9 + 8 + 529 + 68 = 666.

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, 2133813 + ... + 2171643.

It is an arithmetic number, because the mean of its divisors is an integer number (2379159900).

Almost surely, 2^81439852968 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 81439852968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114199675200).

81439852968 is an abundant number, since it is smaller than the sum of its proper divisors (146959497432).

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

81439852968 is a wasteful number, since it uses less digits than its factorization.

81439852968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38903 (or 38896 counting only the distinct ones).

The product of its digits is 29859840, while the sum is 63.

The spelling of 81439852968 in words is "eighty-one billion, four hundred thirty-nine million, eight hundred fifty-two thousand, nine hundred sixty-eight".