2138909 has 2 divisors, whose sum is σ = 2138910. Its totient is φ = 2138908.

The previous prime is 2138897. The next prime is 2138971. The reversal of 2138909 is 9098312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1144900 + 994009 = 1070^2 + 997^2 .

It is a cyclic number.

It is not a de Polignac number, because 2138909 - 2¹² = 2134813 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 (2138989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1069454 + 1069455.

It is an arithmetic number, because the mean of its divisors is an integer number (1069455).

2^2138909 is an apocalyptic number.

It is an amenable number.

2138909 is a deficient number, since it is larger than the sum of its proper divisors (1).

2138909 is an equidigital number, since it uses as much as digits as its factorization.

2138909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 2138909 is about 1462.5009401706. The cubic root of 2138909 is about 128.8439713621.

The spelling of 2138909 in words is "two million, one hundred thirty-eight thousand, nine hundred nine".