816131618 has 8 divisors (see below), whose sum is σ = 1226604060. Its totient is φ = 407263600.

The previous prime is 816131587. The next prime is 816131633.

816131618 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 2 ways, for example, as 605504449 + 210627169 = 24607^2 + 14513^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 399833 + ... + 401868.

Almost surely, 2^816131618 is an apocalyptic number.

816131618 is a deficient number, since it is larger than the sum of its proper divisors (410472442).

816131618 is a wasteful number, since it uses less digits than its factorization.

816131618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 802212.

The product of its digits is 6912, while the sum is 35.

The square root of 816131618 is about 28568.0173970824. The cubic root of 816131618 is about 934.5159850094.

The spelling of 816131618 in words is "eight hundred sixteen million, one hundred thirty-one thousand, six hundred eighteen".