1809149 has 2 divisors, whose sum is σ = 1809150. Its totient is φ = 1809148.

The previous prime is 1809133. The next prime is 1809163. The reversal of 1809149 is 9419081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1612900 + 196249 = 1270^2 + 443^2 .

It is a cyclic number.

It is not a de Polignac number, because 1809149 - 2⁴ = 1809133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1809169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 904574 + 904575.

It is an arithmetic number, because the mean of its divisors is an integer number (904575).

2^1809149 is an apocalyptic number.

It is an amenable number.

1809149 is a deficient number, since it is larger than the sum of its proper divisors (1).

1809149 is an equidigital number, since it uses as much as digits as its factorization.

1809149 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 1809149 is about 1345.0460958644. The cubic root of 1809149 is about 121.8497882541.

The spelling of 1809149 in words is "one million, eight hundred nine thousand, one hundred forty-nine".