505213645421 has 2 divisors, whose sum is σ = 505213645422. Its totient is φ = 505213645420.

The previous prime is 505213645411. The next prime is 505213645507. The reversal of 505213645421 is 124546312505.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 430941044521 + 74272600900 = 656461^2 + 272530^2 .

It is a cyclic number.

It is not a de Polignac number, because 505213645421 - 2¹⁸ = 505213383277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (505213645411) 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, 252606822710 + 252606822711.

It is an arithmetic number, because the mean of its divisors is an integer number (252606822711).

Almost surely, 2^505213645421 is an apocalyptic number.

It is an amenable number.

505213645421 is a deficient number, since it is larger than the sum of its proper divisors (1).

505213645421 is an equidigital number, since it uses as much as digits as its factorization.

505213645421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144000, while the sum is 38.

Adding to 505213645421 its reverse (124546312505), we get a palindrome (629759957926).

The spelling of 505213645421 in words is "five hundred five billion, two hundred thirteen million, six hundred forty-five thousand, four hundred twenty-one".