81475636 has 12 divisors (see below), whose sum is σ = 155544480. Its totient is φ = 37034360.

The previous prime is 81475633. The next prime is 81475643. The reversal of 81475636 is 63657418.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81475631) 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 3 ways as a sum of consecutive naturals, for example, 925816 + ... + 925903.

It is an arithmetic number, because the mean of its divisors is an integer number (12962040).

Almost surely, 2^81475636 is an apocalyptic number.

It is an amenable number.

81475636 is a deficient number, since it is larger than the sum of its proper divisors (74068844).

81475636 is a wasteful number, since it uses less digits than its factorization.

81475636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1851734 (or 1851732 counting only the distinct ones).

The product of its digits is 120960, while the sum is 40.

The square root of 81475636 is about 9026.3855446131. The cubic root of 81475636 is about 433.5201148769.

The spelling of 81475636 in words is "eighty-one million, four hundred seventy-five thousand, six hundred thirty-six".