81587328 has 32 divisors (see below), whose sum is σ = 216717360. Its totient is φ = 27195648.

The previous prime is 81587323. The next prime is 81587339. The reversal of 81587328 is 82378518.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (32).

It is a self number, because there is not a number n which added to its sum of digits gives 81587328.

It is not an unprimeable number, because it can be changed into a prime (81587321) 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, 105850 + ... + 106617.

Almost surely, 2^81587328 is an apocalyptic number.

It is an amenable number.

81587328 is an abundant number, since it is smaller than the sum of its proper divisors (135130032).

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

81587328 is a wasteful number, since it uses less digits than its factorization.

81587328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212484 (or 212472 counting only the distinct ones).

The product of its digits is 107520, while the sum is 42.

The square root of 81587328 is about 9032.5703982864. The cubic root of 81587328 is about 433.7181234343.

The spelling of 81587328 in words is "eighty-one million, five hundred eighty-seven thousand, three hundred twenty-eight".