81871767600 has 960 divisors, whose sum is σ = 333966720000. Its totient is φ = 17117291520.

The previous prime is 81871767569. The next prime is 81871767611. The reversal of 81871767600 is 676717818.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 2823164386 + ... + 2823164414.

It is an arithmetic number, because the mean of its divisors is an integer number (347882000).

Almost surely, 2^81871767600 is an apocalyptic number.

81871767600 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 81871767600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (166983360000).

81871767600 is an abundant number, since it is smaller than the sum of its proper divisors (252094952400).

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

81871767600 is a wasteful number, since it uses less digits than its factorization.

81871767600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128 (or 65 counting only the distinct ones).

The product of its (nonzero) digits is 790272, while the sum is 51.

The spelling of 81871767600 in words is "eighty-one billion, eight hundred seventy-one million, seven hundred sixty-seven thousand, six hundred".