81636246 has 48 divisors (see below), whose sum is σ = 185474016. Its totient is φ = 25901568.

The previous prime is 81636211. The next prime is 81636251. The reversal of 81636246 is 64263618.

It is a self number, because there is not a number n which added to its sum of digits gives 81636246.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 120966 + ... + 121638.

It is an arithmetic number, because the mean of its divisors is an integer number (3864042).

Almost surely, 2^81636246 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81636246, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92737008).

81636246 is an abundant number, since it is smaller than the sum of its proper divisors (103837770).

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

81636246 is a wasteful number, since it uses less digits than its factorization.

81636246 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 997 (or 994 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 81636246 is about 9035.2778595902. The cubic root of 81636246 is about 433.8047887893.

The spelling of 81636246 in words is "eighty-one million, six hundred thirty-six thousand, two hundred forty-six".