212321261 has 2 divisors, whose sum is σ = 212321262. Its totient is φ = 212321260.

The previous prime is 212321203. The next prime is 212321287. The reversal of 212321261 is 162123212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 176092900 + 36228361 = 13270^2 + 6019^2 .

It is a cyclic number.

It is not a de Polignac number, because 212321261 - 2¹⁰ = 212320237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212320261) 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, 106160630 + 106160631.

It is an arithmetic number, because the mean of its divisors is an integer number (106160631).

Almost surely, 2^212321261 is an apocalyptic number.

It is an amenable number.

212321261 is a deficient number, since it is larger than the sum of its proper divisors (1).

212321261 is an equidigital number, since it uses as much as digits as its factorization.

212321261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 288, while the sum is 20.

The square root of 212321261 is about 14571.2477502786. The cubic root of 212321261 is about 596.5742376654.

Adding to 212321261 its reverse (162123212), we get a palindrome (374444473).

The spelling of 212321261 in words is "two hundred twelve million, three hundred twenty-one thousand, two hundred sixty-one".