81799424000 has 288 divisors, whose sum is σ = 237483890280. Its totient is φ = 28041216000.

The previous prime is 81799423961. The next prime is 81799424053. The reversal of 81799424000 is 42499718.

It can be written as a sum of positive squares in 4 ways, for example, as 44429894656 + 37369529344 = 210784^2 + 193312^2 .

It is a super-2 number, since 2×81799424000² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12540740 + ... + 12547260.

Almost surely, 2^81799424000 is an apocalyptic number.

81799424000 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 81799424000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118741945140).

81799424000 is an abundant number, since it is smaller than the sum of its proper divisors (155684466280).

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

81799424000 is an equidigital number, since it uses as much as digits as its factorization.

81799424000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6572 (or 6535 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 44.

The spelling of 81799424000 in words is "eighty-one billion, seven hundred ninety-nine million, four hundred twenty-four thousand".