520855390421 has 2 divisors, whose sum is σ = 520855390422. Its totient is φ = 520855390420.

The previous prime is 520855390411. The next prime is 520855390483. The reversal of 520855390421 is 124093558025.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 313180140625 + 207675249796 = 559625^2 + 455714^2 .

It is a cyclic number.

It is not a de Polignac number, because 520855390421 - 2⁶ = 520855390357 is a prime.

It is a super-2 number, since 2×520855390421² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (520855390411) 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 as a sum of consecutive naturals, namely, 260427695210 + 260427695211.

It is an arithmetic number, because the mean of its divisors is an integer number (260427695211).

Almost surely, 2^520855390421 is an apocalyptic number.

It is an amenable number.

520855390421 is a deficient number, since it is larger than the sum of its proper divisors (1).

520855390421 is an equidigital number, since it uses as much as digits as its factorization.

520855390421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432000, while the sum is 44.

The spelling of 520855390421 in words is "five hundred twenty billion, eight hundred fifty-five million, three hundred ninety thousand, four hundred twenty-one".