1900009 has 2 divisors, whose sum is σ = 1900010. Its totient is φ = 1900008.

The previous prime is 1899983. The next prime is 1900037. The reversal of 1900009 is 9000091.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1742400 + 157609 = 1320^2 + 397^2 .

It is a cyclic number.

It is not a de Polignac number, because 1900009 - 2⁹ = 1899497 is a prime.

It is a super-2 number, since 2×1900009² = 7220068400162, which contains 22 as substring.

It is a Chen prime.

1900009 is a lucky number.

It is a nialpdrome in base 12.

It is not a weakly prime, because it can be changed into another prime (1900049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 950004 + 950005.

It is an arithmetic number, because the mean of its divisors is an integer number (950005).

2^1900009 is an apocalyptic number.

It is an amenable number.

1900009 is a deficient number, since it is larger than the sum of its proper divisors (1).

1900009 is an equidigital number, since it uses as much as digits as its factorization.

1900009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 81, while the sum is 19.

The square root of 1900009 is about 1378.4081398483. The cubic root of 1900009 is about 123.8564285252.

The spelling of 1900009 in words is "one million, nine hundred thousand, nine".