212001221009 has 2 divisors, whose sum is σ = 212001221010. Its totient is φ = 212001221008.

The previous prime is 212001220997. The next prime is 212001221041. The reversal of 212001221009 is 900122100212.

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., 187621521409 + 24379699600 = 433153^2 + 156140^2 .

It is a cyclic number.

It is not a de Polignac number, because 212001221009 - 2¹² = 212001216913 is a prime.

It is not a weakly prime, because it can be changed into another prime (212001221609) 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, 106000610504 + 106000610505.

It is an arithmetic number, because the mean of its divisors is an integer number (106000610505).

Almost surely, 2^212001221009 is an apocalyptic number.

It is an amenable number.

212001221009 is a deficient number, since it is larger than the sum of its proper divisors (1).

212001221009 is an equidigital number, since it uses as much as digits as its factorization.

212001221009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 20.

The spelling of 212001221009 in words is "two hundred twelve billion, one million, two hundred twenty-one thousand, nine".