1098509 has 2 divisors, whose sum is σ = 1098510. Its totient is φ = 1098508.

The previous prime is 1098481. The next prime is 1098511. The reversal of 1098509 is 9058901.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 940900 + 157609 = 970^2 + 397^2 .

It is an emirp because it is prime and its reverse (9058901) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1098509 is a prime.

Together with 1098511, it forms a pair of twin primes.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1098109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 549254 + 549255.

It is an arithmetic number, because the mean of its divisors is an integer number (549255).

2^1098509 is an apocalyptic number.

It is an amenable number.

1098509 is a deficient number, since it is larger than the sum of its proper divisors (1).

1098509 is an equidigital number, since it uses as much as digits as its factorization.

1098509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 32.

The square root of 1098509 is about 1048.0978007801. The cubic root of 1098509 is about 103.1813501643.

The spelling of 1098509 in words is "one million, ninety-eight thousand, five hundred nine".