42547809 has 4 divisors (see below), whose sum is σ = 56730416. Its totient is φ = 28365204.

The previous prime is 42547807. The next prime is 42547811. The reversal of 42547809 is 90874524.

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 an interprime number because it is at equal distance from previous prime (42547807) and next prime (42547811).

It is not a de Polignac number, because 42547809 - 2¹ = 42547807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42547807) 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 in 3 ways as a sum of consecutive naturals, for example, 7091299 + ... + 7091304.

It is an arithmetic number, because the mean of its divisors is an integer number (14182604).

Almost surely, 2^42547809 is an apocalyptic number.

It is an amenable number.

42547809 is a deficient number, since it is larger than the sum of its proper divisors (14182607).

42547809 is a wasteful number, since it uses less digits than its factorization.

42547809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14182606.

The product of its (nonzero) digits is 80640, while the sum is 39.

The square root of 42547809 is about 6522.8681574902. The cubic root of 42547809 is about 349.1074099546.

The spelling of 42547809 in words is "forty-two million, five hundred forty-seven thousand, eight hundred nine".