1804842989 has 4 divisors (see below), whose sum is σ = 1805163324. Its totient is φ = 1804522656.

The previous prime is 1804842979. The next prime is 1804842997. The reversal of 1804842989 is 9892484081.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9892484081 = 137 ⋅72207913.

It can be written as a sum of positive squares in 2 ways, for example, as 838565764 + 966277225 = 28958^2 + 31085^2 .

It is a cyclic number.

It is not a de Polignac number, because 1804842989 - 2⁸ = 1804842733 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1804842989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1804842979) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 151562 + ... + 163035.

It is an arithmetic number, because the mean of its divisors is an integer number (451290831).

Almost surely, 2^1804842989 is an apocalyptic number.

It is an amenable number.

1804842989 is a deficient number, since it is larger than the sum of its proper divisors (320335).

1804842989 is an equidigital number, since it uses as much as digits as its factorization.

1804842989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320334.

The product of its (nonzero) digits is 1327104, while the sum is 53.

The square root of 1804842989 is about 42483.4437045774. The cubic root of 1804842989 is about 1217.5303864901.

The spelling of 1804842989 in words is "one billion, eight hundred four million, eight hundred forty-two thousand, nine hundred eighty-nine".