21210203213 has 2 divisors, whose sum is σ = 21210203214. Its totient is φ = 21210203212.

The previous prime is 21210203197. The next prime is 21210203239. The reversal of 21210203213 is 31230201212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20732256169 + 477947044 = 143987^2 + 21862^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210203213 - 2⁴ = 21210203197 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21210203191 and 21210203200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21210203513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605101606 + 10605101607.

It is an arithmetic number, because the mean of its divisors is an integer number (10605101607).

Almost surely, 2^21210203213 is an apocalyptic number.

It is an amenable number.

21210203213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210203213 is an equidigital number, since it uses as much as digits as its factorization.

21210203213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21210203213 its reverse (31230201212), we get a palindrome (52440404425).

The spelling of 21210203213 in words is "twenty-one billion, two hundred ten million, two hundred three thousand, two hundred thirteen".