42690509 has 2 divisors, whose sum is σ = 42690510. Its totient is φ = 42690508.

The previous prime is 42690481. The next prime is 42690517. The reversal of 42690509 is 90509624.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40921609 + 1768900 = 6397^2 + 1330^2 .

It is a cyclic number.

It is not a de Polignac number, because 42690509 - 2⁸ = 42690253 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 (42690559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21345254 + 21345255.

It is an arithmetic number, because the mean of its divisors is an integer number (21345255).

Almost surely, 2^42690509 is an apocalyptic number.

It is an amenable number.

42690509 is a deficient number, since it is larger than the sum of its proper divisors (1).

42690509 is an equidigital number, since it uses as much as digits as its factorization.

42690509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 42690509 is about 6533.7974409986. The cubic root of 42690509 is about 349.4972618889.

The spelling of 42690509 in words is "forty-two million, six hundred ninety thousand, five hundred nine".