81065005 has 16 divisors (see below), whose sum is σ = 115009920. Its totient is φ = 53669952.

The previous prime is 81065003. The next prime is 81065011. The reversal of 81065005 is 50056018.

It is not a de Polignac number, because 81065005 - 2¹ = 81065003 is a prime.

It is a super-3 number, since 3×81065005³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81065003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38919 + ... + 40948.

It is an arithmetic number, because the mean of its divisors is an integer number (7188120).

Almost surely, 2^81065005 is an apocalyptic number.

It is an amenable number.

81065005 is a deficient number, since it is larger than the sum of its proper divisors (33944915).

81065005 is a wasteful number, since it uses less digits than its factorization.

81065005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79908.

The product of its (nonzero) digits is 1200, while the sum is 25.

The square root of 81065005 is about 9003.6106646167. The cubic root of 81065005 is about 432.7905851225.

The spelling of 81065005 in words is "eighty-one million, sixty-five thousand, five".