81618293760 has 176 divisors, whose sum is σ = 262007091456. Its totient is φ = 21685174272.

The previous prime is 81618293723. The next prime is 81618293791. The reversal of 81618293760 is 6739281618.

It is a super-3 number, since 3×81618293760³ (a number of 34 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4245129 + ... + 4264311.

It is an arithmetic number, because the mean of its divisors is an integer number (1488676656).

Almost surely, 2^81618293760 is an apocalyptic number.

81618293760 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 81618293760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (131003545728).

81618293760 is an abundant number, since it is smaller than the sum of its proper divisors (180388797696).

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

81618293760 is a wasteful number, since it uses less digits than its factorization.

81618293760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19488 (or 19470 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 51.

The spelling of 81618293760 in words is "eighty-one billion, six hundred eighteen million, two hundred ninety-three thousand, seven hundred sixty".