212121211 has 8 divisors (see below), whose sum is σ = 217033344. Its totient is φ = 207242880.

The previous prime is 212121209. The next prime is 212121289. The reversal of 212121211 is 112121212.

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 212121211 - 2¹ = 212121209 is a prime.

It is a super-2 number, since 2×212121211² = 89990816312213042, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212121191 and 212121200.

It is not an unprimeable number, because it can be changed into a prime (212121911) 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, 4470 + ... + 21076.

It is an arithmetic number, because the mean of its divisors is an integer number (27129168).

Almost surely, 2^212121211 is an apocalyptic number.

212121211 is a deficient number, since it is larger than the sum of its proper divisors (4912133).

212121211 is a wasteful number, since it uses less digits than its factorization.

212121211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16901.

The product of its digits is 16, while the sum is 13.

The square root of 212121211 is about 14564.3815865968. The cubic root of 212121211 is about 596.3868138566.

Adding to 212121211 its reverse (112121212), we get a palindrome (324242423).

Subtracting from 212121211 its reverse (112121212), we obtain a palindrome (99999999).

It can be divided in two parts, 2121212 and 11, that multiplied together give a palindrome (23333332).

The spelling of 212121211 in words is "two hundred twelve million, one hundred twenty-one thousand, two hundred eleven".