42717809 has 4 divisors (see below), whose sum is σ = 42787440. Its totient is φ = 42648180.

The previous prime is 42717767. The next prime is 42717811. The reversal of 42717809 is 90871724.

42717809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 42717809 - 2⁸ = 42717553 is a prime.

It is a super-2 number, since 2×42717809² = 3649622411520962, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (42717839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33887 + ... + 35124.

It is an arithmetic number, because the mean of its divisors is an integer number (10696860).

Almost surely, 2^42717809 is an apocalyptic number.

It is an amenable number.

42717809 is a deficient number, since it is larger than the sum of its proper divisors (69631).

42717809 is an equidigital number, since it uses as much as digits as its factorization.

42717809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69630.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 42717809 is about 6535.8862444201. The cubic root of 42717809 is about 349.5717455962.

The spelling of 42717809 in words is "forty-two million, seven hundred seventeen thousand, eight hundred nine".