81324929648640 has 384 divisors, whose sum is σ = 266459753589120. Its totient is φ = 21167138144256.

The previous prime is 81324929648579. The next prime is 81324929648659. The reversal of 81324929648640 is 4684692942318.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×81324929648640² (a number of 29 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 314105479 + ... + 314364281.

It is an arithmetic number, because the mean of its divisors is an integer number (693905608305).

Almost surely, 2^{81324929648640} is an apocalyptic number.

81324929648640 is a gapful number since it is divisible by the number (80) 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 81324929648640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133229876794560).

81324929648640 is an abundant number, since it is smaller than the sum of its proper divisors (185134823940480).

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

81324929648640 is a wasteful number, since it uses less digits than its factorization.

81324929648640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259079 (or 259059 counting only the distinct ones).

The product of its (nonzero) digits is 143327232, while the sum is 66.

The spelling of 81324929648640 in words is "eighty-one trillion, three hundred twenty-four billion, nine hundred twenty-nine million, six hundred forty-eight thousand, six hundred forty".