81682997760 has 480 divisors, whose sum is σ = 348182714880. Its totient is φ = 17233772544.

The previous prime is 81682997743. The next prime is 81682997771. The reversal of 81682997760 is 6779928618.

It is a tau number, because it is divible by the number of its divisors (480).

It is a super-2 number, since 2×81682997760² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2077161 + ... + 2116119.

It is an arithmetic number, because the mean of its divisors is an integer number (725380656).

Almost surely, 2^81682997760 is an apocalyptic number.

81682997760 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 81682997760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (174091357440).

81682997760 is an abundant number, since it is smaller than the sum of its proper divisors (266499717120).

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

81682997760 is a wasteful number, since it uses less digits than its factorization.

81682997760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39008 (or 38989 counting only the distinct ones).

The product of its (nonzero) digits is 18289152, while the sum is 63.

The spelling of 81682997760 in words is "eighty-one billion, six hundred eighty-two million, nine hundred ninety-seven thousand, seven hundred sixty".