81240807648 has 768 divisors, whose sum is σ = 299050665984. Its totient is φ = 18632540160.

The previous prime is 81240807577. The next prime is 81240807671. The reversal of 81240807648 is 84670804218.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a junction number, because it is equal to n+sod(n) for n = 81240807597 and 81240807606.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 259555140 + ... + 259555452.

It is an arithmetic number, because the mean of its divisors is an integer number (389388888).

Almost surely, 2^81240807648 is an apocalyptic number.

81240807648 is a gapful number since it is divisible by the number (88) 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 81240807648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149525332992).

81240807648 is an abundant number, since it is smaller than the sum of its proper divisors (217809858336).

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

81240807648 is a wasteful number, since it uses less digits than its factorization.

81240807648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 467 (or 459 counting only the distinct ones).

The product of its (nonzero) digits is 688128, while the sum is 48.

It can be divided in two parts, 81240 and 807648, that added together give a palindrome (888888).

The spelling of 81240807648 in words is "eighty-one billion, two hundred forty million, eight hundred seven thousand, six hundred forty-eight".