81783328 has 96 divisors (see below), whose sum is σ = 189423360. Its totient is φ = 34344960.

The previous prime is 81783259. The next prime is 81783329. The reversal of 81783328 is 82338718.

It is not an unprimeable number, because it can be changed into a prime (81783329) 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, 472650 + ... + 472822.

It is an arithmetic number, because the mean of its divisors is an integer number (1973160).

Almost surely, 2^81783328 is an apocalyptic number.

81783328 is a gapful number since it is divisible by the number (88) 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 81783328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94711680).

81783328 is an abundant number, since it is smaller than the sum of its proper divisors (107640032).

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

81783328 is a wasteful number, since it uses less digits than its factorization.

81783328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290 (or 282 counting only the distinct ones).

The product of its digits is 64512, while the sum is 40.

The square root of 81783328 is about 9043.4135148184. The cubic root of 81783328 is about 434.0651575953.

The spelling of 81783328 in words is "eighty-one million, seven hundred eighty-three thousand, three hundred twenty-eight".