81585104 has 20 divisors (see below), whose sum is σ = 161748576. Its totient is φ = 39843552.

The previous prime is 81585103. The next prime is 81585109. The reversal of 81585104 is 40158518.

It is a super-2 number, since 2×81585104² = 13312258389381632, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81585103) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58604 + ... + 59979.

Almost surely, 2^81585104 is an apocalyptic number.

It is an amenable number.

81585104 is a deficient number, since it is larger than the sum of its proper divisors (80163472).

81585104 is a wasteful number, since it uses less digits than its factorization.

81585104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118634 (or 118628 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 32.

The square root of 81585104 is about 9032.4472874188. The cubic root of 81585104 is about 433.7141824715.

The spelling of 81585104 in words is "eighty-one million, five hundred eighty-five thousand, one hundred four".