42578609 has 2 divisors, whose sum is σ = 42578610. Its totient is φ = 42578608.

The previous prime is 42578597. The next prime is 42578611. The reversal of 42578609 is 90687524.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 32035600 + 10543009 = 5660^2 + 3247^2 .

It is a cyclic number.

It is not a de Polignac number, because 42578609 - 2²⁰ = 41530033 is a prime.

Together with 42578611, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (42578689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21289304 + 21289305.

It is an arithmetic number, because the mean of its divisors is an integer number (21289305).

Almost surely, 2^42578609 is an apocalyptic number.

It is an amenable number.

42578609 is a deficient number, since it is larger than the sum of its proper divisors (1).

42578609 is an equidigital number, since it uses as much as digits as its factorization.

42578609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 41.

The square root of 42578609 is about 6525.2286549975. The cubic root of 42578609 is about 349.1916282725.

The spelling of 42578609 in words is "forty-two million, five hundred seventy-eight thousand, six hundred nine".