520278221 has 4 divisors (see below), whose sum is σ = 525642012. Its totient is φ = 514914432.

The previous prime is 520278181. The next prime is 520278223. The reversal of 520278221 is 122872025.

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 302272996 + 218005225 = 17386^2 + 14765^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-520278221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (520278223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2681750 + ... + 2681943.

It is an arithmetic number, because the mean of its divisors is an integer number (131410503).

Almost surely, 2^520278221 is an apocalyptic number.

It is an amenable number.

520278221 is a deficient number, since it is larger than the sum of its proper divisors (5363791).

520278221 is an equidigital number, since it uses as much as digits as its factorization.

520278221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5363790.

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 520278221 is about 22809.6080851908. The cubic root of 520278221 is about 804.2885428579.

The spelling of 520278221 in words is "five hundred twenty million, two hundred seventy-eight thousand, two hundred twenty-one".