81276477984 has 144 divisors (see below), whose sum is σ = 249096556800. Its totient is φ = 24989326848.

The previous prime is 81276477967. The next prime is 81276477991. The reversal of 81276477984 is 48977467218.

81276477984 is a `hidden beast` number, since 8 + 1 + 2 + 76 + 477 + 98 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5455057 + ... + 5469935.

It is an arithmetic number, because the mean of its divisors is an integer number (1729837200).

Almost surely, 2^81276477984 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 81276477984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124548278400).

81276477984 is an abundant number, since it is smaller than the sum of its proper divisors (167820078816).

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

81276477984 is a wasteful number, since it uses less digits than its factorization.

81276477984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16367 (or 16356 counting only the distinct ones).

The product of its digits is 37933056, while the sum is 63.

The spelling of 81276477984 in words is "eighty-one billion, two hundred seventy-six million, four hundred seventy-seven thousand, nine hundred eighty-four".