81709041 has 16 divisors (see below), whose sum is σ = 115614720. Its totient is φ = 51218640.

The previous prime is 81709039. The next prime is 81709051. The reversal of 81709041 is 14090718.

It is not a de Polignac number, because 81709041 - 2¹ = 81709039 is a prime.

It is a super-2 number, since 2×81709041² = 13352734762279362, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81709051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5965 + ... + 14106.

It is an arithmetic number, because the mean of its divisors is an integer number (7225920).

Almost surely, 2^81709041 is an apocalyptic number.

It is an amenable number.

81709041 is a deficient number, since it is larger than the sum of its proper divisors (33905679).

81709041 is a wasteful number, since it uses less digits than its factorization.

81709041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20156.

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 81709041 is about 9039.3053383543. The cubic root of 81709041 is about 433.9336916542.

Adding to 81709041 its reverse (14090718), we get a palindrome (95799759).

The spelling of 81709041 in words is "eighty-one million, seven hundred nine thousand, forty-one".