81825751512 has 192 divisors, whose sum is σ = 229806720000. Its totient is φ = 26289349632.

The previous prime is 81825751507. The next prime is 81825751523. The reversal of 81825751512 is 21515752818.

It is a happy number.

81825751512 is a `hidden beast` number, since 8 + 1 + 82 + 5 + 7 + 51 + 512 = 666.

It is a super-2 number, since 2×81825751512² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

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 47 ways as a sum of consecutive naturals, for example, 52824114 + ... + 52825662.

It is an arithmetic number, because the mean of its divisors is an integer number (1196910000).

Almost surely, 2^81825751512 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 81825751512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114903360000).

81825751512 is an abundant number, since it is smaller than the sum of its proper divisors (147980968488).

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

81825751512 is a wasteful number, since it uses less digits than its factorization.

81825751512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1850 (or 1843 counting only the distinct ones).

The product of its digits is 224000, while the sum is 45.

The spelling of 81825751512 in words is "eighty-one billion, eight hundred twenty-five million, seven hundred fifty-one thousand, five hundred twelve".