1805999999 has 2 divisors, whose sum is σ = 1806000000. Its totient is φ = 1805999998.

The previous prime is 1805999983. The next prime is 1806000041. The reversal of 1805999999 is 9999995081.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1805999999 - 2⁴ = 1805999983 is a prime.

1805999999 is a modest number, since divided by 99999 gives 18059 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1805929999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 902999999 + 903000000.

It is an arithmetic number, because the mean of its divisors is an integer number (903000000).

Almost surely, 2^1805999999 is an apocalyptic number.

1805999999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1805999999 is an equidigital number, since it uses as much as digits as its factorization.

1805999999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21257640, while the sum is 68.

The square root of 1805999999 is about 42497.0587099860. The cubic root of 1805999999 is about 1217.7905003300.

The spelling of 1805999999 in words is "one billion, eight hundred five million, nine hundred ninety-nine thousand, nine hundred ninety-nine".