42506539 has 2 divisors, whose sum is σ = 42506540. Its totient is φ = 42506538.

The previous prime is 42506533. The next prime is 42506587. The reversal of 42506539 is 93560524.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42506539 - 2³ = 42506531 is a prime.

It is not a weakly prime, because it can be changed into another prime (42506531) 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 as a sum of consecutive naturals, namely, 21253269 + 21253270.

It is an arithmetic number, because the mean of its divisors is an integer number (21253270).

Almost surely, 2^42506539 is an apocalyptic number.

42506539 is a deficient number, since it is larger than the sum of its proper divisors (1).

42506539 is an equidigital number, since it uses as much as digits as its factorization.

42506539 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32400, while the sum is 34.

The square root of 42506539 is about 6519.7039043196. The cubic root of 42506539 is about 348.9944991374.

It can be divided in two parts, 425065 and 39, that added together give a square (425104 = 652²).

The spelling of 42506539 in words is "forty-two million, five hundred six thousand, five hundred thirty-nine".