42087509 has 2 divisors, whose sum is σ = 42087510. Its totient is φ = 42087508.

The previous prime is 42087503. The next prime is 42087523. The reversal of 42087509 is 90578024.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39025009 + 3062500 = 6247^2 + 1750^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42087509 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42087503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21043754 + 21043755.

It is an arithmetic number, because the mean of its divisors is an integer number (21043755).

Almost surely, 2^42087509 is an apocalyptic number.

It is an amenable number.

42087509 is a deficient number, since it is larger than the sum of its proper divisors (1).

42087509 is an equidigital number, since it uses as much as digits as its factorization.

42087509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 42087509 is about 6487.4886512425. The cubic root of 42087509 is about 347.8439125835.

The spelling of 42087509 in words is "forty-two million, eighty-seven thousand, five hundred nine".