42390239 has 2 divisors, whose sum is σ = 42390240. Its totient is φ = 42390238.

The previous prime is 42390223. The next prime is 42390241. The reversal of 42390239 is 93209324.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 42390239 - 2⁴ = 42390223 is a prime.

Together with 42390241, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42390259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21195119 + 21195120.

It is an arithmetic number, because the mean of its divisors is an integer number (21195120).

Almost surely, 2^42390239 is an apocalyptic number.

42390239 is a deficient number, since it is larger than the sum of its proper divisors (1).

42390239 is an equidigital number, since it uses as much as digits as its factorization.

42390239 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 32.

The square root of 42390239 is about 6510.7786784685. The cubic root of 42390239 is about 348.6759196549.

The spelling of 42390239 in words is "forty-two million, three hundred ninety thousand, two hundred thirty-nine".