81055618 has 16 divisors (see below), whose sum is σ = 139475520. Its totient is φ = 34607376.

The previous prime is 81055613. The next prime is 81055627. The reversal of 81055618 is 81655018.

It is not an unprimeable number, because it can be changed into a prime (81055613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6996 + ... + 14527.

It is an arithmetic number, because the mean of its divisors is an integer number (8717220).

Almost surely, 2^81055618 is an apocalyptic number.

81055618 is a deficient number, since it is larger than the sum of its proper divisors (58419902).

81055618 is a wasteful number, since it uses less digits than its factorization.

81055618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21801.

The product of its (nonzero) digits is 9600, while the sum is 34.

The square root of 81055618 is about 9003.0893586591. The cubic root of 81055618 is about 432.7738793440.

The spelling of 81055618 in words is "eighty-one million, fifty-five thousand, six hundred eighteen".