81536375 has 8 divisors (see below), whose sum is σ = 101757552. Its totient is φ = 65229000.

The previous prime is 81536363. The next prime is 81536381. The reversal of 81536375 is 57363518.

It is not a de Polignac number, because 81536375 - 2⁴ = 81536359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 326021 + ... + 326270.

It is an arithmetic number, because the mean of its divisors is an integer number (12719694).

Almost surely, 2^81536375 is an apocalyptic number.

81536375 is a deficient number, since it is larger than the sum of its proper divisors (20221177).

81536375 is an equidigital number, since it uses as much as digits as its factorization.

81536375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 652306 (or 652296 counting only the distinct ones).

The product of its digits is 75600, while the sum is 38.

The square root of 81536375 is about 9029.7494428140. The cubic root of 81536375 is about 433.6278159394.

The spelling of 81536375 in words is "eighty-one million, five hundred thirty-six thousand, three hundred seventy-five".