81892749600 has 864 divisors, whose sum is σ = 314475872256. Its totient is φ = 20771251200.

The previous prime is 81892749563. The next prime is 81892749611. The reversal of 81892749600 is 694729818.

81892749600 is a `hidden beast` number, since 8 + 1 + 8 + 9 + 27 + 4 + 9 + 600 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a Harshad number since it is a multiple of its sum of digits (54).

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 143 ways as a sum of consecutive naturals, for example, 644824737 + ... + 644824863.

It is an arithmetic number, because the mean of its divisors is an integer number (363976704).

Almost surely, 2^81892749600 is an apocalyptic number.

81892749600 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 81892749600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (157237936128).

81892749600 is an abundant number, since it is smaller than the sum of its proper divisors (232583122656).

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

81892749600 is a wasteful number, since it uses less digits than its factorization.

81892749600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300 (or 275 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 54.

The spelling of 81892749600 in words is "eighty-one billion, eight hundred ninety-two million, seven hundred forty-nine thousand, six hundred".