21102120022221 has 32 divisors (see below), whose sum is σ = 37281868369920. Its totient is φ = 11534078022192.

The previous prime is 21102120022213. The next prime is 21102120022229. The reversal of 21102120022221 is 12222002120112.

It is a happy number.

21102120022221 is a `hidden beast` number, since 211 + 0 + 212 + 0 + 0 + 22 + 221 = 666.

It is an interprime number because it is at equal distance from previous prime (21102120022213) and next prime (21102120022229).

It is not a de Polignac number, because 21102120022221 - 2³ = 21102120022213 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21102120022194 and 21102120022203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102120022229) 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, 2427200625 + ... + 2427209318.

It is an arithmetic number, because the mean of its divisors is an integer number (1165058386560).

Almost surely, 2^{21102120022221} is an apocalyptic number.

21102120022221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21102120022221 is a deficient number, since it is larger than the sum of its proper divisors (16179748347699).

21102120022221 is a wasteful number, since it uses less digits than its factorization.

21102120022221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4854409982 (or 4854409976 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21102120022221 its reverse (12222002120112), we get a palindrome (33324122142333).

The spelling of 21102120022221 in words is "twenty-one trillion, one hundred two billion, one hundred twenty million, twenty-two thousand, two hundred twenty-one".