213003221 has 2 divisors, whose sum is σ = 213003222. Its totient is φ = 213003220.

The previous prime is 213003181. The next prime is 213003223. The reversal of 213003221 is 122300312.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 208947025 + 4056196 = 14455^2 + 2014^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213003221 is a prime.

Together with 213003223, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 213003196 and 213003205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213003223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106501610 + 106501611.

It is an arithmetic number, because the mean of its divisors is an integer number (106501611).

Almost surely, 2^213003221 is an apocalyptic number.

It is an amenable number.

213003221 is a deficient number, since it is larger than the sum of its proper divisors (1).

213003221 is an equidigital number, since it uses as much as digits as its factorization.

213003221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 213003221 is about 14594.6298685510. The cubic root of 213003221 is about 597.2122723134.

Adding to 213003221 its reverse (122300312), we get a palindrome (335303533).

The spelling of 213003221 in words is "two hundred thirteen million, three thousand, two hundred twenty-one".