81585804 has 12 divisors (see below), whose sum is σ = 190366904. Its totient is φ = 27195264.

The previous prime is 81585799. The next prime is 81585811. The reversal of 81585804 is 40858518.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3399397 + ... + 3399420.

Almost surely, 2^81585804 is an apocalyptic number.

It is an amenable number.

81585804 is an abundant number, since it is smaller than the sum of its proper divisors (108781100).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81585804 is a wasteful number, since it uses less digits than its factorization.

81585804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6798824 (or 6798822 counting only the distinct ones).

The product of its (nonzero) digits is 51200, while the sum is 39.

The square root of 81585804 is about 9032.4860365239. The cubic root of 81585804 is about 433.7154228902.

The spelling of 81585804 in words is "eighty-one million, five hundred eighty-five thousand, eight hundred four".