211221221100021 has 24 divisors (see below), whose sum is σ = 339915001855104. Its totient is φ = 125289183370560.

The previous prime is 211221221099983. The next prime is 211221221100067. The reversal of 211221221100021 is 120001122122112.

211221221100021 is a `hidden beast` number, since 211 + 221 + 2 + 211 + 0 + 0 + 0 + 21 = 666.

It is not a de Polignac number, because 211221221100021 - 2⁴¹ = 209022197844469 is a prime.

It is a super-2 number, since 2×211221221100021² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 211221221099967 and 211221221100003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211221221104021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22697311176 + ... + 22697320481.

It is an arithmetic number, because the mean of its divisors is an integer number (14163125077296).

Almost surely, 2^{211221221100021} is an apocalyptic number.

It is an amenable number.

211221221100021 is a deficient number, since it is larger than the sum of its proper divisors (128693780755083).

211221221100021 is a wasteful number, since it uses less digits than its factorization.

211221221100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45394631721 (or 45394631718 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 211221221100021 its reverse (120001122122112), we get a palindrome (331222343222133).

The spelling of 211221221100021 in words is "two hundred eleven trillion, two hundred twenty-one billion, two hundred twenty-one million, one hundred thousand, twenty-one".