2143909 has 2 divisors, whose sum is σ = 2143910. Its totient is φ = 2143908.

The previous prime is 2143901. The next prime is 2143943. The reversal of 2143909 is 9093412.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1898884 + 245025 = 1378^2 + 495^2 .

It is a cyclic number.

It is not a de Polignac number, because 2143909 - 2³ = 2143901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2143901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1071954 + 1071955.

It is an arithmetic number, because the mean of its divisors is an integer number (1071955).

2^2143909 is an apocalyptic number.

It is an amenable number.

2143909 is a deficient number, since it is larger than the sum of its proper divisors (1).

2143909 is an equidigital number, since it uses as much as digits as its factorization.

2143909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 2143909 is about 1464.2093429561. The cubic root of 2143909 is about 128.9442901886.

The spelling of 2143909 in words is "two million, one hundred forty-three thousand, nine hundred nine".