81135330 has 64 divisors (see below), whose sum is σ = 202953600. Its totient is φ = 20733440.

The previous prime is 81135317. The next prime is 81135331. The reversal of 81135330 is 3353118.

It is a self number, because there is not a number n which added to its sum of digits gives 81135330.

It is not an unprimeable number, because it can be changed into a prime (81135331) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 155470 + ... + 155990.

It is an arithmetic number, because the mean of its divisors is an integer number (3171150).

Almost surely, 2^81135330 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81135330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101476800).

81135330 is an abundant number, since it is smaller than the sum of its proper divisors (121818270).

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

81135330 is a wasteful number, since it uses less digits than its factorization.

81135330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 739.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 81135330 is about 9007.5151956575. The cubic root of 81135330 is about 432.9156995329.

Adding to 81135330 its reverse (3353118), we get a palindrome (84488448).

The spelling of 81135330 in words is "eighty-one million, one hundred thirty-five thousand, three hundred thirty".