81007881682 has 24 divisors (see below), whose sum is σ = 150374736576. Its totient is φ = 32047073136.

The previous prime is 81007881679. The next prime is 81007881683. The reversal of 81007881682 is 28618870018.

It is a super-2 number, since 2×81007881682² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (81007881683) 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 11 ways as a sum of consecutive naturals, for example, 17116798 + ... + 17121529.

It is an arithmetic number, because the mean of its divisors is an integer number (6265614024).

Almost surely, 2^81007881682 is an apocalyptic number.

81007881682 is a deficient number, since it is larger than the sum of its proper divisors (69366854894).

81007881682 is a wasteful number, since it uses less digits than its factorization.

81007881682 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34238362 (or 34238349 counting only the distinct ones).

The product of its (nonzero) digits is 344064, while the sum is 49.

The spelling of 81007881682 in words is "eighty-one billion, seven million, eight hundred eighty-one thousand, six hundred eighty-two".