42212209 has 4 divisors (see below), whose sum is σ = 45459316. Its totient is φ = 38965104.

The previous prime is 42212189. The next prime is 42212237. The reversal of 42212209 is 90221224.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2560000 + 39652209 = 1600^2 + 6297^2 .

It is a cyclic number.

It is not a de Polignac number, because 42212209 - 2¹³ = 42204017 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 42212209.

It is not an unprimeable number, because it can be changed into a prime (42212279) 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 in 3 ways as a sum of consecutive naturals, for example, 1623534 + ... + 1623559.

It is an arithmetic number, because the mean of its divisors is an integer number (11364829).

Almost surely, 2^42212209 is an apocalyptic number.

It is an amenable number.

42212209 is a deficient number, since it is larger than the sum of its proper divisors (3247107).

42212209 is a wasteful number, since it uses less digits than its factorization.

42212209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3247106.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 42212209 is about 6497.0923496592. The cubic root of 42212209 is about 348.1871131194.

The spelling of 42212209 in words is "forty-two million, two hundred twelve thousand, two hundred nine".