81065915 has 16 divisors (see below), whose sum is σ = 116011008. Its totient is φ = 53170656.

The previous prime is 81065903. The next prime is 81065987. The reversal of 81065915 is 51956018.

It is not a de Polignac number, because 81065915 - 2⁸ = 81065659 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a Duffinian number.

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, 49547 + ... + 51156.

It is an arithmetic number, because the mean of its divisors is an integer number (7250688).

Almost surely, 2^81065915 is an apocalyptic number.

81065915 is a deficient number, since it is larger than the sum of its proper divisors (34945093).

81065915 is a wasteful number, since it uses less digits than its factorization.

81065915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100738.

The product of its (nonzero) digits is 10800, while the sum is 35.

The square root of 81065915 is about 9003.6611997565. The cubic root of 81065915 is about 432.7922045551.

The spelling of 81065915 in words is "eighty-one million, sixty-five thousand, nine hundred fifteen".