81604334 has 16 divisors (see below), whose sum is σ = 140010336. Its totient is φ = 34944000.

The previous prime is 81604331. The next prime is 81604339. The reversal of 81604334 is 43340618.

It is a junction number, because it is equal to n+sod(n) for n = 81604297 and 81604306.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81604331) 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, 27734 + ... + 30534.

It is an arithmetic number, because the mean of its divisors is an integer number (8750646).

Almost surely, 2^81604334 is an apocalyptic number.

81604334 is a deficient number, since it is larger than the sum of its proper divisors (58406002).

81604334 is a wasteful number, since it uses less digits than its factorization.

81604334 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4891.

The product of its (nonzero) digits is 6912, while the sum is 29.

The square root of 81604334 is about 9033.5117202559. The cubic root of 81604334 is about 433.7482559650.

The spelling of 81604334 in words is "eighty-one million, six hundred four thousand, three hundred thirty-four".