1806432989 has 2 divisors, whose sum is σ = 1806432990. Its totient is φ = 1806432988.

The previous prime is 1806432977. The next prime is 1806433003. The reversal of 1806432989 is 9892346081.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1485485764 + 320947225 = 38542^2 + 17915^2 .

It is an emirp because it is prime and its reverse (9892346081) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1806432989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1806432289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 903216494 + 903216495.

It is an arithmetic number, because the mean of its divisors is an integer number (903216495).

Almost surely, 2^1806432989 is an apocalyptic number.

It is an amenable number.

1806432989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1806432989 is an equidigital number, since it uses as much as digits as its factorization.

1806432989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 746496, while the sum is 50.

The square root of 1806432989 is about 42502.1527572428. The cubic root of 1806432989 is about 1217.8878146480.

The spelling of 1806432989 in words is "one billion, eight hundred six million, four hundred thirty-two thousand, nine hundred eighty-nine".