21120021101221 has 32 divisors (see below), whose sum is σ = 25427801907200. Its totient is φ = 17136422907840.

The previous prime is 21120021101177. The next prime is 21120021101227. The reversal of 21120021101221 is 12210112002112.

It is a cyclic number.

It is not a de Polignac number, because 21120021101221 - 2²¹ = 21120019004069 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21120021101195 and 21120021101204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120021101227) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2168597770 + ... + 2168607508.

It is an arithmetic number, because the mean of its divisors is an integer number (794618809600).

Almost surely, 2^{21120021101221} is an apocalyptic number.

It is an amenable number.

21120021101221 is a deficient number, since it is larger than the sum of its proper divisors (4307780805979).

21120021101221 is a wasteful number, since it uses less digits than its factorization.

21120021101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21089.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21120021101221 its reverse (12210112002112), we get a palindrome (33330133103333).

The spelling of 21120021101221 in words is "twenty-one trillion, one hundred twenty billion, twenty-one million, one hundred one thousand, two hundred twenty-one".