1808081138 has 24 divisors (see below), whose sum is σ = 2967334236. Its totient is φ = 823399680.

The previous prime is 1808081089. The next prime is 1808081153. The reversal of 1808081138 is 8311808081.

It can be written as a sum of positive squares in 2 ways, for example, as 1795810129 + 12271009 = 42377^2 + 3503^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5006 + ... + 60342.

Almost surely, 2^1808081138 is an apocalyptic number.

1808081138 is a deficient number, since it is larger than the sum of its proper divisors (1159253098).

1808081138 is a wasteful number, since it uses less digits than its factorization.

1808081138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55418 (or 55387 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 38.

The square root of 1808081138 is about 42521.5373428572. The cubic root of 1808081138 is about 1218.2580932478.

The spelling of 1808081138 in words is "one billion, eight hundred eight million, eighty-one thousand, one hundred thirty-eight".