212101221 has 8 divisors (see below), whose sum is σ = 283037760. Its totient is φ = 141282752.

The previous prime is 212101207. The next prime is 212101223. The reversal of 212101221 is 122101212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 212101221 - 2⁹ = 212100709 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212101197 and 212101206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212101223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25236 + ... + 32573.

It is an arithmetic number, because the mean of its divisors is an integer number (35379720).

Almost surely, 2^212101221 is an apocalyptic number.

It is an amenable number.

212101221 is a deficient number, since it is larger than the sum of its proper divisors (70936539).

212101221 is a wasteful number, since it uses less digits than its factorization.

212101221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59035.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 212101221 is about 14563.6953071671. The cubic root of 212101221 is about 596.3680790542.

Adding to 212101221 its reverse (122101212), we get a palindrome (334202433).

Subtracting from 212101221 its reverse (122101212), we obtain a palindrome (90000009).

The spelling of 212101221 in words is "two hundred twelve million, one hundred one thousand, two hundred twenty-one".