81030560 has 96 divisors (see below), whose sum is σ = 208293120. Its totient is φ = 29611008.

The previous prime is 81030557. The next prime is 81030577. The reversal of 81030560 is 6503018.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 338921 + ... + 339159.

It is an arithmetic number, because the mean of its divisors is an integer number (2169720).

Almost surely, 2^81030560 is an apocalyptic number.

81030560 is a gapful number since it is divisible by the number (80) 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 81030560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104146560).

81030560 is an abundant number, since it is smaller than the sum of its proper divisors (127262560).

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

81030560 is a wasteful number, since it uses less digits than its factorization.

81030560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430 (or 422 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 81030560 is about 9001.6976176719. The cubic root of 81030560 is about 432.7292780121.

Adding to 81030560 its reverse (6503018), we get a palindrome (87533578).

The spelling of 81030560 in words is "eighty-one million, thirty thousand, five hundred sixty".