81344000 has 160 divisors (see below), whose sum is σ = 214486272. Its totient is φ = 30720000.

The previous prime is 81343993. The next prime is 81344023. The reversal of 81344000 is 44318.

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (20).

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, 1983980 + ... + 1984020.

Almost surely, 2^81344000 is an apocalyptic number.

81344000 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 81344000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107243136).

81344000 is an abundant number, since it is smaller than the sum of its proper divisors (133142272).

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

81344000 is an equidigital number, since it uses as much as digits as its factorization.

81344000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105 (or 79 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 81344000 is about 9019.0908632744. The cubic root of 81344000 is about 433.2865169672.

Adding to 81344000 its reverse (44318), we get a palindrome (81388318).

The spelling of 81344000 in words is "eighty-one million, three hundred forty-four thousand".