21112012221221 has 16 divisors (see below), whose sum is σ = 22230866236800. Its totient is φ = 19993929062400.

The previous prime is 21112012221211. The next prime is 21112012221233. The reversal of 21112012221221 is 12212221021112.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21112012221221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21112012221193 and 21112012221202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112012221211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1072700501 + ... + 1072720181.

It is an arithmetic number, because the mean of its divisors is an integer number (1389429139800).

Almost surely, 2^{21112012221221} is an apocalyptic number.

It is an amenable number.

21112012221221 is a deficient number, since it is larger than the sum of its proper divisors (1118854015579).

21112012221221 is a wasteful number, since it uses less digits than its factorization.

21112012221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36380.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 21112012221221 its reverse (12212221021112), we get a palindrome (33324233242333).

The spelling of 21112012221221 in words is "twenty-one trillion, one hundred twelve billion, twelve million, two hundred twenty-one thousand, two hundred twenty-one".