213205533421 has 2 divisors, whose sum is σ = 213205533422. Its totient is φ = 213205533420.

The previous prime is 213205533407. The next prime is 213205533449. The reversal of 213205533421 is 124335502312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 203247688900 + 9957844521 = 450830^2 + 99789^2 .

It is a cyclic number.

It is not a de Polignac number, because 213205533421 - 2⁷ = 213205533293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213205533451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106602766710 + 106602766711.

It is an arithmetic number, because the mean of its divisors is an integer number (106602766711).

Almost surely, 2^213205533421 is an apocalyptic number.

It is an amenable number.

213205533421 is a deficient number, since it is larger than the sum of its proper divisors (1).

213205533421 is an equidigital number, since it uses as much as digits as its factorization.

213205533421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21600, while the sum is 31.

The spelling of 213205533421 in words is "two hundred thirteen billion, two hundred five million, five hundred thirty-three thousand, four hundred twenty-one".