1816631999 has 32 divisors (see below), whose sum is σ = 2262556800. Its totient is φ = 1420296192.

The previous prime is 1816631953. The next prime is 1816632029. The reversal of 1816631999 is 9991366181.

It is a happy number.

It is not a de Polignac number, because 1816631999 - 2²⁸ = 1548196543 is a prime.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 1816631999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1816631699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4045727 + ... + 4046175.

It is an arithmetic number, because the mean of its divisors is an integer number (70704900).

Almost surely, 2^1816631999 is an apocalyptic number.

1816631999 is a deficient number, since it is larger than the sum of its proper divisors (445924801).

1816631999 is a wasteful number, since it uses less digits than its factorization.

1816631999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 899.

The product of its digits is 629856, while the sum is 53.

The square root of 1816631999 is about 42621.9661559624. The cubic root of 1816631999 is about 1220.1755545542.

The spelling of 1816631999 in words is "one billion, eight hundred sixteen million, six hundred thirty-one thousand, nine hundred ninety-nine".