211221211112021 has 12 divisors (see below), whose sum is σ = 234467469937932. Its totient is φ = 190118101800000.

The previous prime is 211221211112017. The next prime is 211221211112027. The reversal of 211221211112021 is 120211112122112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 184447934107921 + 26773277004100 = 13581161^2 + 5174290^2 .

It is not a de Polignac number, because 211221211112021 - 2² = 211221211112017 is a prime.

It is a super-2 number, since 2×211221211112021² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 211221211111984 and 211221211112002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211221211112027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8641719680 + ... + 8641744121.

It is an arithmetic number, because the mean of its divisors is an integer number (19538955828161).

Almost surely, 2^{211221211112021} is an apocalyptic number.

It is an amenable number.

211221211112021 is a deficient number, since it is larger than the sum of its proper divisors (23246258825911).

211221211112021 is a wasteful number, since it uses less digits than its factorization.

211221211112021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17283463924 (or 17283463913 counting only the distinct ones).

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

Adding to 211221211112021 its reverse (120211112122112), we get a palindrome (331432323234133).

The spelling of 211221211112021 in words is "two hundred eleven trillion, two hundred twenty-one billion, two hundred eleven million, one hundred twelve thousand, twenty-one".