1841805989 has 2 divisors, whose sum is σ = 1841805990. Its totient is φ = 1841805988.

The previous prime is 1841805941. The next prime is 1841805997. The reversal of 1841805989 is 9895081481.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1778730625 + 63075364 = 42175^2 + 7942^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1841805989 is a prime.

It is a super-2 number, since 2×1841805989² = 6784498602232536242, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1841805989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1841805919) 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 as a sum of consecutive naturals, namely, 920902994 + 920902995.

It is an arithmetic number, because the mean of its divisors is an integer number (920902995).

Almost surely, 2^1841805989 is an apocalyptic number.

It is an amenable number.

1841805989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1841805989 is an equidigital number, since it uses as much as digits as its factorization.

1841805989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 829440, while the sum is 53.

The square root of 1841805989 is about 42916.2671839013. The cubic root of 1841805989 is about 1225.7859155579.

The spelling of 1841805989 in words is "one billion, eight hundred forty-one million, eight hundred five thousand, nine hundred eighty-nine".