213221251 has 2 divisors, whose sum is σ = 213221252. Its totient is φ = 213221250.

The previous prime is 213221243. The next prime is 213221377. The reversal of 213221251 is 152122312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 213221251 - 2³ = 213221243 is a prime.

It is not a weakly prime, because it can be changed into another prime (213221551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106610625 + 106610626.

It is an arithmetic number, because the mean of its divisors is an integer number (106610626).

Almost surely, 2^213221251 is an apocalyptic number.

213221251 is a deficient number, since it is larger than the sum of its proper divisors (1).

213221251 is an equidigital number, since it uses as much as digits as its factorization.

213221251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 240, while the sum is 19.

The square root of 213221251 is about 14602.0974863202. The cubic root of 213221251 is about 597.4159715637.

Adding to 213221251 its reverse (152122312), we get a palindrome (365343563).

The spelling of 213221251 in words is "two hundred thirteen million, two hundred twenty-one thousand, two hundred fifty-one".