212912321 has 2 divisors, whose sum is σ = 212912322. Its totient is φ = 212912320.

The previous prime is 212912317. The next prime is 212912339. The reversal of 212912321 is 123219212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 212722225 + 190096 = 14585^2 + 436^2 .

It is a cyclic number.

It is not a de Polignac number, because 212912321 - 2² = 212912317 is a prime.

It is not a weakly prime, because it can be changed into another prime (212912351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106456160 + 106456161.

It is an arithmetic number, because the mean of its divisors is an integer number (106456161).

Almost surely, 2^212912321 is an apocalyptic number.

It is an amenable number.

212912321 is a deficient number, since it is larger than the sum of its proper divisors (1).

212912321 is an equidigital number, since it uses as much as digits as its factorization.

212912321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432, while the sum is 23.

The square root of 212912321 is about 14591.5153770950. The cubic root of 212912321 is about 597.1273059617.

The spelling of 212912321 in words is "two hundred twelve million, nine hundred twelve thousand, three hundred twenty-one".