1949809 has 2 divisors, whose sum is σ = 1949810. Its totient is φ = 1949808.

The previous prime is 1949791. The next prime is 1949813. The reversal of 1949809 is 9089491.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1056784 + 893025 = 1028^2 + 945^2 .

It is a cyclic number.

It is not a de Polignac number, because 1949809 - 2⁵ = 1949777 is a prime.

It is a Chen prime.

1949809 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (1949819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 974904 + 974905.

It is an arithmetic number, because the mean of its divisors is an integer number (974905).

2^1949809 is an apocalyptic number.

It is an amenable number.

1949809 is a deficient number, since it is larger than the sum of its proper divisors (1).

1949809 is an equidigital number, since it uses as much as digits as its factorization.

1949809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 1949809 is about 1396.3556137317. The cubic root of 1949809 is about 124.9292185942.

The spelling of 1949809 in words is "one million, nine hundred forty-nine thousand, eight hundred nine".