81018455418 has 64 divisors (see below), whose sum is σ = 190580860800. Its totient is φ = 25468490880.

The previous prime is 81018455393. The next prime is 81018455423. The reversal of 81018455418 is 81455481018.

81018455418 is a `hidden beast` number, since 8 + 1 + 0 + 1 + 84 + 554 + 18 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 534243 + ... + 668918.

It is an arithmetic number, because the mean of its divisors is an integer number (2977825950).

Almost surely, 2^81018455418 is an apocalyptic number.

81018455418 is an abundant number, since it is smaller than the sum of its proper divisors (109562405382).

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

81018455418 is a wasteful number, since it uses less digits than its factorization.

81018455418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1203244 (or 1203238 counting only the distinct ones).

The product of its (nonzero) digits is 204800, while the sum is 45.

The spelling of 81018455418 in words is "eighty-one billion, eighteen million, four hundred fifty-five thousand, four hundred eighteen".