521866201 has 4 divisors (see below), whose sum is σ = 521928100. Its totient is φ = 521804304.

The previous prime is 521866181. The next prime is 521866207. The reversal of 521866201 is 102668125.

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 2 ways, for example, as 151880976 + 369985225 = 12324^2 + 19235^2 .

It is a cyclic number.

It is not a de Polignac number, because 521866201 - 2⁷ = 521866073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521866207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15846 + ... + 35983.

It is an arithmetic number, because the mean of its divisors is an integer number (130482025).

Almost surely, 2^521866201 is an apocalyptic number.

It is an amenable number.

521866201 is a deficient number, since it is larger than the sum of its proper divisors (61899).

521866201 is a wasteful number, since it uses less digits than its factorization.

521866201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61898.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 521866201 is about 22844.3910183660. The cubic root of 521866201 is about 805.1059881280.

The spelling of 521866201 in words is "five hundred twenty-one million, eight hundred sixty-six thousand, two hundred one".