42098909 has 2 divisors, whose sum is σ = 42098910. Its totient is φ = 42098908.

The previous prime is 42098891. The next prime is 42098911. The reversal of 42098909 is 90989024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27825625 + 14273284 = 5275^2 + 3778^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42098909 is a prime.

It is a Sophie Germain prime.

Together with 42098911, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42098929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21049454 + 21049455.

It is an arithmetic number, because the mean of its divisors is an integer number (21049455).

Almost surely, 2^42098909 is an apocalyptic number.

It is an amenable number.

42098909 is a deficient number, since it is larger than the sum of its proper divisors (1).

42098909 is an equidigital number, since it uses as much as digits as its factorization.

42098909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 42098909 is about 6488.3672060080. The cubic root of 42098909 is about 347.8753159042.

The spelling of 42098909 in words is "forty-two million, ninety-eight thousand, nine hundred nine".