2009639 has 2 divisors, whose sum is σ = 2009640. Its totient is φ = 2009638.

The previous prime is 2009603. The next prime is 2009647. The reversal of 2009639 is 9369002.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2009639 - 2²⁰ = 961063 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2009669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1004819 + 1004820.

It is an arithmetic number, because the mean of its divisors is an integer number (1004820).

2^2009639 is an apocalyptic number.

2009639 is a deficient number, since it is larger than the sum of its proper divisors (1).

2009639 is an equidigital number, since it uses as much as digits as its factorization.

2009639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 29.

The square root of 2009639 is about 1417.6173672751. The cubic root of 2009639 is about 126.1941870082.

The spelling of 2009639 in words is "two million, nine thousand, six hundred thirty-nine".