521268217 has 4 divisors (see below), whose sum is σ = 523296756. Its totient is φ = 519239680.

The previous prime is 521268199. The next prime is 521268233. The reversal of 521268217 is 712862125.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 511257321 + 10010896 = 22611^2 + 3164^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-521268217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521268277) 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 3 ways as a sum of consecutive naturals, for example, 1013884 + ... + 1014397.

It is an arithmetic number, because the mean of its divisors is an integer number (130824189).

Almost surely, 2^521268217 is an apocalyptic number.

It is an amenable number.

521268217 is a deficient number, since it is larger than the sum of its proper divisors (2028539).

521268217 is a wasteful number, since it uses less digits than its factorization.

521268217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2028538.

The product of its digits is 13440, while the sum is 34.

The square root of 521268217 is about 22831.2990650992. The cubic root of 521268217 is about 804.7983585078.

The spelling of 521268217 in words is "five hundred twenty-one million, two hundred sixty-eight thousand, two hundred seventeen".