520398421 has 2 divisors, whose sum is σ = 520398422. Its totient is φ = 520398420.

The previous prime is 520398413. The next prime is 520398491. The reversal of 520398421 is 124893025.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 383180625 + 137217796 = 19575^2 + 11714^2 .

It is a cyclic number.

It is not a de Polignac number, because 520398421 - 2³ = 520398413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (520398491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260199210 + 260199211.

It is an arithmetic number, because the mean of its divisors is an integer number (260199211).

Almost surely, 2^520398421 is an apocalyptic number.

It is an amenable number.

520398421 is a deficient number, since it is larger than the sum of its proper divisors (1).

520398421 is an equidigital number, since it uses as much as digits as its factorization.

520398421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 520398421 is about 22812.2427875911. The cubic root of 520398421 is about 804.3504764125.

The spelling of 520398421 in words is "five hundred twenty million, three hundred ninety-eight thousand, four hundred twenty-one".