81365328 has 120 divisors (see below), whose sum is σ = 256578816. Its totient is φ = 23846400.

The previous prime is 81365327. The next prime is 81365357. The reversal of 81365328 is 82356318.

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 = 81365292 and 81365301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81365321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 48276 + ... + 49932.

Almost surely, 2^81365328 is an apocalyptic number.

81365328 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 81365328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128289408).

81365328 is an abundant number, since it is smaller than the sum of its proper divisors (175213488).

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

81365328 is a wasteful number, since it uses less digits than its factorization.

81365328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1713 (or 1704 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 81365328 is about 9020.2731665953. The cubic root of 81365328 is about 433.3243821951.

The spelling of 81365328 in words is "eighty-one million, three hundred sixty-five thousand, three hundred twenty-eight".