81853317744 has 160 divisors (see below), whose sum is σ = 241334553600. Its totient is φ = 23683891200.

The previous prime is 81853317647. The next prime is 81853317757. The reversal of 81853317744 is 44771335818.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 977232 + ... + 1057680.

It is an arithmetic number, because the mean of its divisors is an integer number (1508340960).

Almost surely, 2^81853317744 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 81853317744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120667276800).

81853317744 is an abundant number, since it is smaller than the sum of its proper divisors (159481235856).

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

81853317744 is a wasteful number, since it uses less digits than its factorization.

81853317744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80559 (or 80553 counting only the distinct ones).

The product of its digits is 2257920, while the sum is 51.

The spelling of 81853317744 in words is "eighty-one billion, eight hundred fifty-three million, three hundred seventeen thousand, seven hundred forty-four".