81130070 has 16 divisors (see below), whose sum is σ = 166896288. Its totient is φ = 27816000.

The previous prime is 81130043. The next prime is 81130073. The reversal of 81130070 is 7003118.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81130073) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 579431 + ... + 579570.

It is an arithmetic number, because the mean of its divisors is an integer number (10431018).

Almost surely, 2^81130070 is an apocalyptic number.

81130070 is an abundant number, since it is smaller than the sum of its proper divisors (85766218).

81130070 is a wasteful number, since it uses less digits than its factorization.

81130070 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1159015.

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 81130070 is about 9007.2232125112. The cubic root of 81130070 is about 432.9063440286.

Adding to 81130070 its reverse (7003118), we get a palindrome (88133188).

The spelling of 81130070 in words is "eighty-one million, one hundred thirty thousand, seventy".