81530686 has 8 divisors (see below), whose sum is σ = 123844320. Its totient is φ = 40249248.

The previous prime is 81530681. The next prime is 81530693. The reversal of 81530686 is 68603518.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81530681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 257851 + ... + 258166.

It is an arithmetic number, because the mean of its divisors is an integer number (15480540).

Almost surely, 2^81530686 is an apocalyptic number.

81530686 is a deficient number, since it is larger than the sum of its proper divisors (42313634).

81530686 is a wasteful number, since it uses less digits than its factorization.

81530686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 516098.

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 81530686 is about 9029.4344230411. The cubic root of 81530686 is about 433.6177306001.

The spelling of 81530686 in words is "eighty-one million, five hundred thirty thousand, six hundred eighty-six".