42138539 has 2 divisors, whose sum is σ = 42138540. Its totient is φ = 42138538.

The previous prime is 42138533. The next prime is 42138557. The reversal of 42138539 is 93583124.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42138539 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 42138499 and 42138508.

It is not a weakly prime, because it can be changed into another prime (42138533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21069269 + 21069270.

It is an arithmetic number, because the mean of its divisors is an integer number (21069270).

Almost surely, 2^42138539 is an apocalyptic number.

42138539 is a deficient number, since it is larger than the sum of its proper divisors (1).

42138539 is an equidigital number, since it uses as much as digits as its factorization.

42138539 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 35.

The square root of 42138539 is about 6491.4204146704. The cubic root of 42138539 is about 347.9844396751.

The spelling of 42138539 in words is "forty-two million, one hundred thirty-eight thousand, five hundred thirty-nine".