42517202809 has 3 divisors (see below), whose sum is σ = 42517409007. Its totient is φ = 42516996612.

The previous prime is 42517202797. The next prime is 42517202857. The reversal of 42517202809 is 90820271524.

The square root of 42517202809 is 206197.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 42450421225 + 66781584 = 206035^2 + 8172^2 .

It is not a de Polignac number, because 42517202809 - 2¹⁵ = 42517170041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42517202869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 103099 + ... + 309295.

It is an arithmetic number, because the mean of its divisors is an integer number (14172469669).

Almost surely, 2^42517202809 is an apocalyptic number.

42517202809 is the 206197-th square number.

42517202809 is the 103099-th centered octagonal number.

It is an amenable number.

42517202809 is a deficient number, since it is larger than the sum of its proper divisors (206198).

42517202809 is an frugal number, since it uses more digits than its factorization.

42517202809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 412394 (or 206197 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 40.

The spelling of 42517202809 in words is "forty-two billion, five hundred seventeen million, two hundred two thousand, eight hundred nine".