81455418 has 48 divisors (see below), whose sum is σ = 196649856. Its totient is φ = 24155520.

The previous prime is 81455417. The next prime is 81455431.

81455418 is nontrivially palindromic in base 10.

It is not an unprimeable number, because it can be changed into a prime (81455417) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4930 + ... + 13682.

It is an arithmetic number, because the mean of its divisors is an integer number (4096872).

Almost surely, 2^81455418 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81455418, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98324928).

81455418 is an abundant number, since it is smaller than the sum of its proper divisors (115194438).

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

81455418 is a wasteful number, since it uses less digits than its factorization.

81455418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8819 (or 8816 counting only the distinct ones).

The product of its digits is 25600, while the sum is 36.

The square root of 81455418 is about 9025.2655362599. The cubic root of 81455418 is about 433.4842528892.

The spelling of 81455418 in words is "eighty-one million, four hundred fifty-five thousand, four hundred eighteen".