210012221 has 4 divisors (see below), whose sum is σ = 210087612. Its totient is φ = 209936832.

The previous prime is 210012193. The next prime is 210012223. The reversal of 210012221 is 122210012.

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 80371225 + 129640996 = 8965^2 + 11386^2 .

It is a cyclic number.

It is not a de Polignac number, because 210012221 - 2⁶ = 210012157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210012223) 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 in 3 ways as a sum of consecutive naturals, for example, 33350 + ... + 39143.

It is an arithmetic number, because the mean of its divisors is an integer number (52521903).

Almost surely, 2^210012221 is an apocalyptic number.

It is an amenable number.

210012221 is a deficient number, since it is larger than the sum of its proper divisors (75391).

210012221 is an equidigital number, since it uses as much as digits as its factorization.

210012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75390.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 210012221 is about 14491.7984046149. The cubic root of 210012221 is about 594.4037253178.

Adding to 210012221 its reverse (122210012), we get a palindrome (332222233).

The spelling of 210012221 in words is "two hundred ten million, twelve thousand, two hundred twenty-one".