4218509 has 2 divisors, whose sum is σ = 4218510. Its totient is φ = 4218508.

The previous prime is 4218497. The next prime is 4218517. The reversal of 4218509 is 9058124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4141225 + 77284 = 2035^2 + 278^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4218509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4218569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2109254 + 2109255.

It is an arithmetic number, because the mean of its divisors is an integer number (2109255).

Almost surely, 2^4218509 is an apocalyptic number.

It is an amenable number.

4218509 is a deficient number, since it is larger than the sum of its proper divisors (1).

4218509 is an equidigital number, since it uses as much as digits as its factorization.

4218509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 4218509 is about 2053.9009226348. The cubic root of 4218509 is about 161.5795248419.

The spelling of 4218509 in words is "four million, two hundred eighteen thousand, five hundred nine".