81528525 has 120 divisors (see below), whose sum is σ = 172245920. Its totient is φ = 37791360.

The previous prime is 81528523. The next prime is 81528547. The reversal of 81528525 is 52582518.

81528525 is a `hidden beast` number, since 81 + 52 + 8 + 525 = 666.

It is not a de Polignac number, because 81528525 - 2¹ = 81528523 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81528525.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81528521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 500094 + ... + 500256.

Almost surely, 2^81528525 is an apocalyptic number.

It is an amenable number.

81528525 is an abundant number, since it is smaller than the sum of its proper divisors (90717395).

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

81528525 is a wasteful number, since it uses less digits than its factorization.

81528525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217 (or 203 counting only the distinct ones).

The product of its digits is 32000, while the sum is 36.

The square root of 81528525 is about 9029.3147580533. The cubic root of 81528525 is about 433.6138995019.

The spelling of 81528525 in words is "eighty-one million, five hundred twenty-eight thousand, five hundred twenty-five".