1800099999 has 12 divisors (see below), whose sum is σ = 2613619216. Its totient is φ = 1193847552.

The previous prime is 1800099989. The next prime is 1800100007. The reversal of 1800099999 is 9999900081.

It is not a de Polignac number, because 1800099999 - 2⁵ = 1800099967 is a prime.

It is a Duffinian number.

1800099999 is a modest number, since divided by 99999 gives 18000 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1800099929) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 516427 + ... + 519900.

Almost surely, 2^1800099999 is an apocalyptic number.

1800099999 is a deficient number, since it is larger than the sum of its proper divisors (813519217).

1800099999 is a wasteful number, since it uses less digits than its factorization.

1800099999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1036526 (or 1036523 counting only the distinct ones).

The product of its (nonzero) digits is 472392, while the sum is 54.

The square root of 1800099999 is about 42427.5853543423. The cubic root of 1800099999 is about 1216.4629251463.

The spelling of 1800099999 in words is "one billion, eight hundred million, ninety-nine thousand, nine hundred ninety-nine".