42611209 has 2 divisors, whose sum is σ = 42611210. Its totient is φ = 42611208.

The previous prime is 42611207. The next prime is 42611221. The reversal of 42611209 is 90211624.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41925625 + 685584 = 6475^2 + 828^2 .

It is a cyclic number.

It is not a de Polignac number, because 42611209 - 2¹ = 42611207 is a prime.

Together with 42611207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (42611207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21305604 + 21305605.

It is an arithmetic number, because the mean of its divisors is an integer number (21305605).

Almost surely, 2^42611209 is an apocalyptic number.

It is an amenable number.

42611209 is a deficient number, since it is larger than the sum of its proper divisors (1).

42611209 is an equidigital number, since it uses as much as digits as its factorization.

42611209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 42611209 is about 6527.7261737913. The cubic root of 42611209 is about 349.2807242084.

The spelling of 42611209 in words is "forty-two million, six hundred eleven thousand, two hundred nine".