81235206 has 48 divisors (see below), whose sum is σ = 196101360. Its totient is φ = 24131520.

The previous prime is 81235199. The next prime is 81235207. The reversal of 81235206 is 60253218.

It is a self number, because there is not a number n which added to its sum of digits gives 81235206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81235207) 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 23 ways as a sum of consecutive naturals, for example, 801 + ... + 12771.

It is an arithmetic number, because the mean of its divisors is an integer number (4085445).

Almost surely, 2^81235206 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81235206, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98050680).

81235206 is an abundant number, since it is smaller than the sum of its proper divisors (114866154).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81235206 is a wasteful number, since it uses less digits than its factorization.

81235206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12021 (or 12018 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 81235206 is about 9013.0575278315. The cubic root of 81235206 is about 433.0932636054.

The spelling of 81235206 in words is "eighty-one million, two hundred thirty-five thousand, two hundred six".