81451053825984 has 672 divisors, whose sum is σ = 252362285150976. Its totient is φ = 25026434334720.

The previous prime is 81451053825961. The next prime is 81451053826031. The reversal of 81451053825984 is 48952835015418.

81451053825984 is a `hidden beast` number, since 8 + 1 + 4 + 5 + 1 + 0 + 5 + 38 + 2 + 598 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 42137119482 + ... + 42137121414.

It is an arithmetic number, because the mean of its divisors is an integer number (375539114808).

Almost surely, 2^{81451053825984} 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 81451053825984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (126181142575488).

81451053825984 is an abundant number, since it is smaller than the sum of its proper divisors (170911231324992).

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

81451053825984 is a wasteful number, since it uses less digits than its factorization.

81451053825984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2513 (or 2500 counting only the distinct ones).

The product of its (nonzero) digits is 55296000, while the sum is 63.

The spelling of 81451053825984 in words is "eighty-one trillion, four hundred fifty-one billion, fifty-three million, eight hundred twenty-five thousand, nine hundred eighty-four".