81130680 has 128 divisors (see below), whose sum is σ = 276883200. Its totient is φ = 21119616.

The previous prime is 81130657. The next prime is 81130697. The reversal of 81130680 is 8603118.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 45567 + ... + 47313.

It is an arithmetic number, because the mean of its divisors is an integer number (2163150).

Almost surely, 2^81130680 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 81130680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138441600).

81130680 is an abundant number, since it is smaller than the sum of its proper divisors (195752520).

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

81130680 is a wasteful number, since it uses less digits than its factorization.

81130680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1810 (or 1800 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 81130680 is about 9007.2570741597. The cubic root of 81130680 is about 432.9074290032.

Adding to 81130680 its reverse (8603118), we get a palindrome (89733798).

It can be divided in two parts, 81130 and 680, that added together give a triangular number (81810 = T₄₀₄).

The spelling of 81130680 in words is "eighty-one million, one hundred thirty thousand, six hundred eighty".