81575325 has 54 divisors (see below), whose sum is σ = 158297594. Its totient is φ = 39919680.

The previous prime is 81575317. The next prime is 81575327. The reversal of 81575325 is 52357518.

81575325 is a `hidden beast` number, since 81 + 575 + 3 + 2 + 5 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 251001 + 81324324 = 501^2 + 9018^2 .

It is not a de Polignac number, because 81575325 - 2³ = 81575317 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81575325.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81575327) 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 53 ways as a sum of consecutive naturals, for example, 488392 + ... + 488558.

Almost surely, 2^81575325 is an apocalyptic number.

It is an amenable number.

81575325 is a deficient number, since it is larger than the sum of its proper divisors (76722269).

81575325 is a wasteful number, since it uses less digits than its factorization.

81575325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 363 (or 188 counting only the distinct ones).

The product of its digits is 42000, while the sum is 36.

The square root of 81575325 is about 9031.9059450373. The cubic root of 81575325 is about 433.6968530807.

The spelling of 81575325 in words is "eighty-one million, five hundred seventy-five thousand, three hundred twenty-five".