81787860000 has 1440 divisors, whose sum is σ = 379626730560. Its totient is φ = 16934400000.

The previous prime is 81787859921. The next prime is 81787860031. The reversal of 81787860000 is 6878718.

It is a tau number, because it is divible by the number of its divisors (1440).

It is a Harshad number since it is a multiple of its sum of digits (45).

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 239 ways as a sum of consecutive naturals, for example, 291059860 + ... + 291060140.

It is an arithmetic number, because the mean of its divisors is an integer number (263629674).

Almost surely, 2^81787860000 is an apocalyptic number.

81787860000 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 81787860000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (189813365280).

81787860000 is an abundant number, since it is smaller than the sum of its proper divisors (297838870560).

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

81787860000 is a wasteful number, since it uses less digits than its factorization.

81787860000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345 (or 309 counting only the distinct ones).

The product of its (nonzero) digits is 150528, while the sum is 45.

The spelling of 81787860000 in words is "eighty-one billion, seven hundred eighty-seven million, eight hundred sixty thousand".