81915024464 has 160 divisors (see below), whose sum is σ = 208593315840. Its totient is φ = 30278707200.

The previous prime is 81915024449. The next prime is 81915024481. The reversal of 81915024464 is 46442051918.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1277654 + ... + 1340234.

It is an arithmetic number, because the mean of its divisors is an integer number (1303708224).

Almost surely, 2^81915024464 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 81915024464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104296657920).

81915024464 is an abundant number, since it is smaller than the sum of its proper divisors (126678291376).

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

81915024464 is a wasteful number, since it uses less digits than its factorization.

81915024464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62669 (or 62663 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 44.

The spelling of 81915024464 in words is "eighty-one billion, nine hundred fifteen million, twenty-four thousand, four hundred sixty-four".