81111530 has 32 divisors (see below), whose sum is σ = 150525648. Its totient is φ = 31449600.

The previous prime is 81111529. The next prime is 81111553. The reversal of 81111530 is 3511118.

It can be written as a sum of positive squares in 8 ways, for example, as 13756681 + 67354849 = 3709^2 + 8207^2 .

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, 73664 + ... + 74756.

Almost surely, 2^81111530 is an apocalyptic number.

81111530 is a deficient number, since it is larger than the sum of its proper divisors (69414118).

81111530 is a wasteful number, since it uses less digits than its factorization.

81111530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1322.

The product of its (nonzero) digits is 120, while the sum is 20.

The square root of 81111530 is about 9006.1939797009. The cubic root of 81111530 is about 432.8733653189.

Adding to 81111530 its reverse (3511118), we get a palindrome (84622648).

The spelling of 81111530 in words is "eighty-one million, one hundred eleven thousand, five hundred thirty".