81236308 has 24 divisors (see below), whose sum is σ = 147417480. Its totient is φ = 39123840.

The previous prime is 81236303. The next prime is 81236317. The reversal of 81236308 is 80363218.

It can be written as a sum of positive squares in 4 ways, for example, as 20164 + 81216144 = 142^2 + 9012^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81236308.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81236303) 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 7 ways as a sum of consecutive naturals, for example, 94810 + ... + 95662.

It is an arithmetic number, because the mean of its divisors is an integer number (6142395).

Almost surely, 2^81236308 is an apocalyptic number.

It is an amenable number.

81236308 is a deficient number, since it is larger than the sum of its proper divisors (66181172).

81236308 is a wasteful number, since it uses less digits than its factorization.

81236308 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1707 (or 1705 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 81236308 is about 9013.1186611516. The cubic root of 81236308 is about 433.0952219789.

The spelling of 81236308 in words is "eighty-one million, two hundred thirty-six thousand, three hundred eight".