82561320 has 96 divisors (see below), whose sum is σ = 271814400. Its totient is φ = 21730176.

The previous prime is 82561313. The next prime is 82561337. The reversal of 82561320 is 2316528.

82561320 is a `hidden beast` number, since 8 + 25 + 613 + 20 = 666.

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 23 ways as a sum of consecutive naturals, for example, 26989 + ... + 29891.

It is an arithmetic number, because the mean of its divisors is an integer number (2831400).

Almost surely, 2^82561320 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 82561320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135907200).

82561320 is an abundant number, since it is smaller than the sum of its proper divisors (189253080).

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

82561320 is a wasteful number, since it uses less digits than its factorization.

82561320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2999 (or 2992 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 82561320 is about 9086.3259901899. The cubic root of 82561320 is about 435.4372140005.

Adding to 82561320 its reverse (2316528), we get a palindrome (84877848).

The spelling of 82561320 in words is "eighty-two million, five hundred sixty-one thousand, three hundred twenty".