81307115 has 8 divisors (see below), whose sum is σ = 98314128. Its totient is φ = 64548640.

The previous prime is 81307111. The next prime is 81307129. The reversal of 81307115 is 51170318.

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

It is not a de Polignac number, because 81307115 - 2² = 81307111 is a prime.

It is a super-2 number, since 2×81307115² = 13221693899246450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81307111) 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, 61412 + ... + 62721.

It is an arithmetic number, because the mean of its divisors is an integer number (12289266).

Almost surely, 2^81307115 is an apocalyptic number.

81307115 is a deficient number, since it is larger than the sum of its proper divisors (17007013).

81307115 is a wasteful number, since it uses less digits than its factorization.

81307115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124269.

The product of its (nonzero) digits is 840, while the sum is 26.

The square root of 81307115 is about 9017.0458022570. The cubic root of 81307115 is about 433.2210165845.

The spelling of 81307115 in words is "eighty-one million, three hundred seven thousand, one hundred fifteen".