81628082618 has 8 divisors (see below), whose sum is σ = 122445052212. Its totient is φ = 40813065216.

The previous prime is 81628082573. The next prime is 81628082621.

It is a happy number.

81628082618 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 2 ways, for example, as 81143510449 + 484572169 = 284857^2 + 22013^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 378605 + ... + 553712.

Almost surely, 2^81628082618 is an apocalyptic number.

81628082618 is a deficient number, since it is larger than the sum of its proper divisors (40816969594).

81628082618 is a wasteful number, since it uses less digits than its factorization.

81628082618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 976096.

The product of its (nonzero) digits is 589824, while the sum is 50.

It can be divided in two parts, 816280 and 82618, that added together give a palindrome (898898).

The spelling of 81628082618 in words is "eighty-one billion, six hundred twenty-eight million, eighty-two thousand, six hundred eighteen".