212221001 has 4 divisors (see below), whose sum is σ = 215128212.
Its totient is φ = 209313792.
The previous prime is 212220997. The next prime is 212221007. The reversal of 212221001 is 100122212.
It is a happy number.
It is a semiprime because it is the product of two primes.
It can be written as a sum of positive squares in 2 ways, for example, as 109725625 + 102495376 = 10475^2 + 10124^2
It is a cyclic number.
It is not a de Polignac number, because 212221001 - 22 = 212220997 is a prime.
It is a Duffinian number.
It is not an unprimeable number, because it can be changed into a prime (212221007) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (13) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1453496 + ... + 1453641.
It is an arithmetic number, because the mean of its divisors is an integer number (53782053).
Almost surely, 2212221001 is an apocalyptic number.
It is an amenable number.
212221001 is a deficient number, since it is larger than the sum of its proper divisors (2907211).
212221001 is an equidigital number, since it uses as much as digits as its factorization.
212221001 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 2907210.
The product of its (nonzero) digits is 16, while the sum is 11.
The square root of 212221001 is about 14567.8070072334.
The cubic root of 212221001 is about 596.4803203159.
Adding to 212221001 its reverse (100122212), we get a palindrome (312343213).
The spelling of 212221001 in words is "two hundred twelve million, two hundred twenty-one thousand, one".