81131060 has 12 divisors (see below), whose sum is σ = 170375268. Its totient is φ = 32452416.

The previous prime is 81131041. The next prime is 81131081. The reversal of 81131060 is 6013118.

It can be written as a sum of positive squares in 2 ways, for example, as 40094224 + 41036836 = 6332^2 + 6406^2 .

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 4056553 = 81131060 / (8 + 1 + 1 + 3 + 1 + 0 + 6 + 0).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2028257 + ... + 2028296.

It is an arithmetic number, because the mean of its divisors is an integer number (14197939).

Almost surely, 2^81131060 is an apocalyptic number.

It is an amenable number.

81131060 is an abundant number, since it is smaller than the sum of its proper divisors (89244208).

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

81131060 is a wasteful number, since it uses less digits than its factorization.

81131060 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4056562 (or 4056560 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 81131060 is about 9007.2781682371. The cubic root of 81131060 is about 432.9081048863.

Adding to 81131060 its reverse (6013118), we get a palindrome (87144178).

The spelling of 81131060 in words is "eighty-one million, one hundred thirty-one thousand, sixty".