81716990940 has 960 divisors, whose sum is σ = 316272781440. Its totient is φ = 17438146560.

The previous prime is 81716990909. The next prime is 81716990947. The reversal of 81716990940 is 4909961718.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81716990947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 278897434 + ... + 278897726.

It is an arithmetic number, because the mean of its divisors is an integer number (329450814).

Almost surely, 2^81716990940 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 81716990940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (158136390720).

81716990940 is an abundant number, since it is smaller than the sum of its proper divisors (234555790500).

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

81716990940 is a wasteful number, since it uses less digits than its factorization.

81716990940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404 (or 393 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 54.

The spelling of 81716990940 in words is "eighty-one billion, seven hundred sixteen million, nine hundred ninety thousand, nine hundred forty".