81536575 has 12 divisors (see below), whose sum is σ = 101497968. Its totient is φ = 64976000.

The previous prime is 81536513. The next prime is 81536599. The reversal of 81536575 is 57563518.

It is not a de Polignac number, because 81536575 - 2¹⁹ = 81012287 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 11 ways as a sum of consecutive naturals, for example, 375 + ... + 12775.

It is an arithmetic number, because the mean of its divisors is an integer number (8458164).

Almost surely, 2^81536575 is an apocalyptic number.

81536575 is a deficient number, since it is larger than the sum of its proper divisors (19961393).

81536575 is a wasteful number, since it uses less digits than its factorization.

81536575 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12674 (or 12669 counting only the distinct ones).

The product of its digits is 126000, while the sum is 40.

The square root of 81536575 is about 9029.7605173116. The cubic root of 81536575 is about 433.6281704867.

The spelling of 81536575 in words is "eighty-one million, five hundred thirty-six thousand, five hundred seventy-five".