81786702816 has 864 divisors, whose sum is σ = 306431693568. Its totient is φ = 20483850240.

The previous prime is 81786702797. The next prime is 81786702821. The reversal of 81786702816 is 61820768718.

It is a happy number.

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 143 ways as a sum of consecutive naturals, for example, 415160830 + ... + 415161026.

It is an arithmetic number, because the mean of its divisors is an integer number (354666312).

Almost surely, 2^81786702816 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 81786702816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153215846784).

81786702816 is an abundant number, since it is smaller than the sum of its proper divisors (224644990752).

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

81786702816 is a wasteful number, since it uses less digits than its factorization.

81786702816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344 (or 326 counting only the distinct ones).

The product of its (nonzero) digits is 1806336, while the sum is 54.

The spelling of 81786702816 in words is "eighty-one billion, seven hundred eighty-six million, seven hundred two thousand, eight hundred sixteen".