81347328 has 90 divisors (see below), whose sum is σ = 242624844. Its totient is φ = 27108864.

The previous prime is 81347323. The next prime is 81347339. The reversal of 81347328 is 82374318.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 81347292 and 81347301.

It is not an unprimeable number, because it can be changed into a prime (81347323) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 18775 + ... + 22697.

Almost surely, 2^81347328 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81347328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121312422).

81347328 is an abundant number, since it is smaller than the sum of its proper divisors (161277516).

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

81347328 is an equidigital number, since it uses as much as digits as its factorization.

81347328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3951 (or 3928 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 81347328 is about 9019.2753589188. The cubic root of 81347328 is about 433.2924258557.

The spelling of 81347328 in words is "eighty-one million, three hundred forty-seven thousand, three hundred twenty-eight".