42809517 has 6 divisors (see below), whose sum is σ = 61835982. Its totient is φ = 28539672.

The previous prime is 42809497. The next prime is 42809537. The reversal of 42809517 is 71590824.

42809517 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (42809497) and next prime (42809537).

It can be written as a sum of positive squares in only one way, i.e., 42068196 + 741321 = 6486^2 + 861^2 .

It is not a de Polignac number, because 42809517 - 2¹⁵ = 42776749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42809537) 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 5 ways as a sum of consecutive naturals, for example, 2378298 + ... + 2378315.

It is an arithmetic number, because the mean of its divisors is an integer number (10305997).

Almost surely, 2^42809517 is an apocalyptic number.

It is an amenable number.

42809517 is a deficient number, since it is larger than the sum of its proper divisors (19026465).

42809517 is a wasteful number, since it uses less digits than its factorization.

42809517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4756619 (or 4756616 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 42809517 is about 6542.8982110377. The cubic root of 42809517 is about 349.8217241749.

The spelling of 42809517 in words is "forty-two million, eight hundred nine thousand, five hundred seventeen".