211021211211221 has 4 divisors (see below), whose sum is σ = 211219725992352. Its totient is φ = 210822696430092.

The previous prime is 211021211211191. The next prime is 211021211211229. The reversal of 211021211211221 is 122112112120112.

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 a cyclic number.

It is not a de Polignac number, because 211021211211221 - 2⁶ = 211021211211157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211021211211193 and 211021211211202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211021211211229) 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, 99257388971 + ... + 99257391096.

It is an arithmetic number, because the mean of its divisors is an integer number (52804931498088).

Almost surely, 2^{211021211211221} is an apocalyptic number.

It is an amenable number.

211021211211221 is a deficient number, since it is larger than the sum of its proper divisors (198514781131).

211021211211221 is a wasteful number, since it uses less digits than its factorization.

211021211211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198514781130.

The product of its (nonzero) digits is 64, while the sum is 20.

Adding to 211021211211221 its reverse (122112112120112), we get a palindrome (333133323331333).

The spelling of 211021211211221 in words is "two hundred eleven trillion, twenty-one billion, two hundred eleven million, two hundred eleven thousand, two hundred twenty-one".