816181618 has 16 divisors (see below), whose sum is σ = 1402410240. Its totient is φ = 348981696.

The previous prime is 816181601. The next prime is 816181637.

816181618 is nontrivially palindromic in base 10.

816181618 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×816181618² = 1332304867122195848, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61258 + ... + 73381.

It is an arithmetic number, because the mean of its divisors is an integer number (87650640).

Almost surely, 2^816181618 is an apocalyptic number.

816181618 is a deficient number, since it is larger than the sum of its proper divisors (586228622).

816181618 is a wasteful number, since it uses less digits than its factorization.

816181618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135081.

The product of its digits is 18432, while the sum is 40.

The square root of 816181618 is about 28568.8924881592. The cubic root of 816181618 is about 934.5350688778.

The spelling of 816181618 in words is "eight hundred sixteen million, one hundred eighty-one thousand, six hundred eighteen".