81338611 has 4 divisors (see below), whose sum is σ = 81390232. Its totient is φ = 81286992.

The previous prime is 81338561. The next prime is 81338651. The reversal of 81338611 is 11683318.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81338611 - 2⁷ = 81338483 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81338651) 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 3 ways as a sum of consecutive naturals, for example, 23370 + ... + 26623.

It is an arithmetic number, because the mean of its divisors is an integer number (20347558).

Almost surely, 2^81338611 is an apocalyptic number.

81338611 is a deficient number, since it is larger than the sum of its proper divisors (51621).

81338611 is a wasteful number, since it uses less digits than its factorization.

81338611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51620.

The product of its digits is 3456, while the sum is 31.

The square root of 81338611 is about 9018.7921031588. The cubic root of 81338611 is about 433.2769484164.

The spelling of 81338611 in words is "eighty-one million, three hundred thirty-eight thousand, six hundred eleven".