81601344000 has 1280 divisors, whose sum is σ = 339194718720. Its totient is φ = 19408896000.

The previous prime is 81601343977. The next prime is 81601344017. The reversal of 81601344000 is 44310618.

It is a tau number, because it is divible by the number of its divisors (1280).

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 1539647974 + ... + 1539648026.

It is an arithmetic number, because the mean of its divisors is an integer number (264995874).

Almost surely, 2^81601344000 is an apocalyptic number.

81601344000 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 81601344000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169597359360).

81601344000 is an abundant number, since it is smaller than the sum of its proper divisors (257593374720).

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

81601344000 is an frugal number, since it uses more digits than its factorization.

81601344000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118 (or 74 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

Adding to 81601344000 its reverse (44310618), we get a palindrome (81645654618).

The spelling of 81601344000 in words is "eighty-one billion, six hundred one million, three hundred forty-four thousand".