81010815 has 8 divisors (see below), whose sum is σ = 129617328. Its totient is φ = 43205760.

The previous prime is 81010799. The next prime is 81010817. The reversal of 81010815 is 51801018.

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

It is not a de Polignac number, because 81010815 - 2⁴ = 81010799 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81010817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2700346 + ... + 2700375.

It is an arithmetic number, because the mean of its divisors is an integer number (16202166).

Almost surely, 2^81010815 is an apocalyptic number.

81010815 is a deficient number, since it is larger than the sum of its proper divisors (48606513).

81010815 is a wasteful number, since it uses less digits than its factorization.

81010815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5400729.

The product of its (nonzero) digits is 320, while the sum is 24.

The square root of 81010815 is about 9000.6008132791. The cubic root of 81010815 is about 432.6941269378.

The spelling of 81010815 in words is "eighty-one million, ten thousand, eight hundred fifteen".