211212120101221 has 4 divisors (see below), whose sum is σ = 212317942719744. Its totient is φ = 210106297482700.

The previous prime is 211212120101209. The next prime is 211212120101233. The reversal of 211212120101221 is 122101021212112.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (211212120101209) and next prime (211212120101233).

It is a cyclic number.

It is not a de Polignac number, because 211212120101221 - 2²⁵ = 211212086546789 is a prime.

It is a super-2 number, since 2×211212120101221² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211212120101321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 552911308975 + ... + 552911309356.

It is an arithmetic number, because the mean of its divisors is an integer number (53079485679936).

Almost surely, 2^{211212120101221} is an apocalyptic number.

It is an amenable number.

211212120101221 is a deficient number, since it is larger than the sum of its proper divisors (1105822618523).

211212120101221 is a wasteful number, since it uses less digits than its factorization.

211212120101221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1105822618522.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 211212120101221 its reverse (122101021212112), we get a palindrome (333313141313333).

The spelling of 211212120101221 in words is "two hundred eleven trillion, two hundred twelve billion, one hundred twenty million, one hundred one thousand, two hundred twenty-one".