1809211489 has 2 divisors, whose sum is σ = 1809211490. Its totient is φ = 1809211488.

The previous prime is 1809211457. The next prime is 1809211493. The reversal of 1809211489 is 9841129081.

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., 1479171600 + 330039889 = 38460^2 + 18167^2 .

It is a cyclic number.

It is not a de Polignac number, because 1809211489 - 2⁵ = 1809211457 is a prime.

It is not a weakly prime, because it can be changed into another prime (1809211409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 904605744 + 904605745.

It is an arithmetic number, because the mean of its divisors is an integer number (904605745).

Almost surely, 2^1809211489 is an apocalyptic number.

It is an amenable number.

1809211489 is a deficient number, since it is larger than the sum of its proper divisors (1).

1809211489 is an equidigital number, since it uses as much as digits as its factorization.

1809211489 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 43.

The square root of 1809211489 is about 42534.8267775949. The cubic root of 1809211489 is about 1218.5119115751.

The spelling of 1809211489 in words is "one billion, eight hundred nine million, two hundred eleven thousand, four hundred eighty-nine".