81244536 has 32 divisors (see below), whose sum is σ = 204144000. Its totient is φ = 26943840.

The previous prime is 81244531. The next prime is 81244543. The reversal of 81244536 is 63544218.

It is a junction number, because it is equal to n+sod(n) for n = 81244497 and 81244506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81244531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3730 + ... + 13281.

It is an arithmetic number, because the mean of its divisors is an integer number (6379500).

Almost surely, 2^81244536 is an apocalyptic number.

It is an amenable number.

81244536 is an abundant number, since it is smaller than the sum of its proper divisors (122899464).

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

81244536 is a wasteful number, since it uses less digits than its factorization.

81244536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17219 (or 17215 counting only the distinct ones).

The product of its digits is 23040, while the sum is 33.

The square root of 81244536 is about 9013.5750953770. The cubic root of 81244536 is about 433.1098434672.

The spelling of 81244536 in words is "eighty-one million, two hundred forty-four thousand, five hundred thirty-six".