213310021 has 2 divisors, whose sum is σ = 213310022. Its totient is φ = 213310020.

The previous prime is 213310007. The next prime is 213310037. The reversal of 213310021 is 120013312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 185368225 + 27941796 = 13615^2 + 5286^2 .

It is a cyclic number.

It is not a de Polignac number, because 213310021 - 2⁵ = 213309989 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 213309983 and 213310010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213310061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106655010 + 106655011.

It is an arithmetic number, because the mean of its divisors is an integer number (106655011).

Almost surely, 2^213310021 is an apocalyptic number.

It is an amenable number.

213310021 is a deficient number, since it is larger than the sum of its proper divisors (1).

213310021 is an equidigital number, since it uses as much as digits as its factorization.

213310021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 213310021 is about 14605.1368018242. The cubic root of 213310021 is about 597.4988670812.

Adding to 213310021 its reverse (120013312), we get a palindrome (333323333).

The spelling of 213310021 in words is "two hundred thirteen million, three hundred ten thousand, twenty-one".