81352580 has 12 divisors (see below), whose sum is σ = 170840460. Its totient is φ = 32541024.

The previous prime is 81352577. The next prime is 81352619. The reversal of 81352580 is 8525318.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 55383364 + 25969216 = 7442^2 + 5096^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2033795 + ... + 2033834.

It is an arithmetic number, because the mean of its divisors is an integer number (14236705).

Almost surely, 2^81352580 is an apocalyptic number.

It is an amenable number.

81352580 is an abundant number, since it is smaller than the sum of its proper divisors (89487880).

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

81352580 is a wasteful number, since it uses less digits than its factorization.

81352580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4067638 (or 4067636 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 32.

The square root of 81352580 is about 9019.5665084304. The cubic root of 81352580 is about 433.3017504924.

Adding to 81352580 its reverse (8525318), we get a palindrome (89877898).

The spelling of 81352580 in words is "eighty-one million, three hundred fifty-two thousand, five hundred eighty".