81818064 has 60 divisors (see below), whose sum is σ = 230077536. Its totient is φ = 27141696.

The previous prime is 81818003. The next prime is 81818069. The reversal of 81818064 is 46081818.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81818069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31437 + ... + 33939.

Almost surely, 2^81818064 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81818064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115038768).

81818064 is an abundant number, since it is smaller than the sum of its proper divisors (148259472).

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

81818064 is a wasteful number, since it uses less digits than its factorization.

81818064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2744 (or 2735 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The square root of 81818064 is about 9045.3338246855. Note that the first 3 decimals coincide. The cubic root of 81818064 is about 434.1266026907.

The spelling of 81818064 in words is "eighty-one million, eight hundred eighteen thousand, sixty-four".