81604311 has 8 divisors (see below), whose sum is σ = 108850560. Its totient is φ = 54380472.

The previous prime is 81604279. The next prime is 81604321. The reversal of 81604311 is 11340618.

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

It is not a de Polignac number, because 81604311 - 2⁵ = 81604279 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81604321) 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 7 ways as a sum of consecutive naturals, for example, 6856 + ... + 14498.

It is an arithmetic number, because the mean of its divisors is an integer number (13606320).

Almost surely, 2^81604311 is an apocalyptic number.

81604311 is a deficient number, since it is larger than the sum of its proper divisors (27246249).

81604311 is a wasteful number, since it uses less digits than its factorization.

81604311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11205.

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 81604311 is about 9033.5104472182. The cubic root of 81604311 is about 433.7482152147.

Adding to 81604311 its reverse (11340618), we get a palindrome (92944929).

The spelling of 81604311 in words is "eighty-one million, six hundred four thousand, three hundred eleven".