81034320 has 80 divisors (see below), whose sum is σ = 253769472. Its totient is φ = 21388800.

The previous prime is 81034273. The next prime is 81034321. The reversal of 81034320 is 2343018.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×81034320² = 13133122035724800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81034321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22569 + ... + 25911.

Almost surely, 2^81034320 is an apocalyptic number.

81034320 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 81034320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (126884736).

81034320 is an abundant number, since it is smaller than the sum of its proper divisors (172735152).

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

81034320 is a wasteful number, since it uses less digits than its factorization.

81034320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3460 (or 3454 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 81034320 is about 9001.9064647440. The cubic root of 81034320 is about 432.7359711121.

Adding to 81034320 its reverse (2343018), we get a palindrome (83377338).

The spelling of 81034320 in words is "eighty-one million, thirty-four thousand, three hundred twenty".