81128571600 has 240 divisors, whose sum is σ = 272485845504. Its totient is φ = 20594112000.

The previous prime is 81128571583. The next prime is 81128571611. The reversal of 81128571600 is 617582118.

It is a tau number, because it is divible by the number of its divisors (240).

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, 5816635 + ... + 5830565.

Almost surely, 2^81128571600 is an apocalyptic number.

81128571600 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 81128571600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136242922752).

81128571600 is an abundant number, since it is smaller than the sum of its proper divisors (191357273904).

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

81128571600 is a wasteful number, since it uses less digits than its factorization.

81128571600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14186 (or 14175 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 39.

The spelling of 81128571600 in words is "eighty-one billion, one hundred twenty-eight million, five hundred seventy-one thousand, six hundred".