211220111221221 has 8 divisors (see below), whose sum is σ = 281633844720640. Its totient is φ = 140809892601312.

The previous prime is 211220111221201. The next prime is 211220111221237. The reversal of 211220111221221 is 122122111022112.

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

It is not a de Polignac number, because 211220111221221 - 2⁶ = 211220111221157 is a prime.

It is a super-2 number, since 2×211220111221221² (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 (211220111221201) 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, 878579656 + ... + 878820033.

It is an arithmetic number, because the mean of its divisors is an integer number (35204230590080).

Almost surely, 2^{211220111221221} is an apocalyptic number.

It is an amenable number.

211220111221221 is a deficient number, since it is larger than the sum of its proper divisors (70413733499419).

211220111221221 is a wasteful number, since it uses less digits than its factorization.

211220111221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1757439755.

The product of its (nonzero) digits is 128, while the sum is 21.

Adding to 211220111221221 its reverse (122122111022112), we get a palindrome (333342222243333).

The spelling of 211220111221221 in words is "two hundred eleven trillion, two hundred twenty billion, one hundred eleven million, two hundred twenty-one thousand, two hundred twenty-one".