213503205521 has 2 divisors, whose sum is σ = 213503205522. Its totient is φ = 213503205520.

The previous prime is 213503205481. The next prime is 213503205533. The reversal of 213503205521 is 125502305312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 209741100625 + 3762104896 = 457975^2 + 61336^2 .

It is a cyclic number.

It is not a de Polignac number, because 213503205521 - 2⁶ = 213503205457 is a prime.

It is not a weakly prime, because it can be changed into another prime (213503205551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106751602760 + 106751602761.

It is an arithmetic number, because the mean of its divisors is an integer number (106751602761).

Almost surely, 2^213503205521 is an apocalyptic number.

It is an amenable number.

213503205521 is a deficient number, since it is larger than the sum of its proper divisors (1).

213503205521 is an equidigital number, since it uses as much as digits as its factorization.

213503205521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9000, while the sum is 29.

The spelling of 213503205521 in words is "two hundred thirteen billion, five hundred three million, two hundred five thousand, five hundred twenty-one".