21121112002221 has 48 divisors (see below), whose sum is σ = 38036785438080. Its totient is φ = 10971862824960.

The previous prime is 21121112002141. The next prime is 21121112002231. The reversal of 21121112002221 is 12220021112112.

21121112002221 is a `hidden beast` number, since 211 + 21 + 11 + 200 + 2 + 221 = 666.

It is not a de Polignac number, because 21121112002221 - 2¹¹ = 21121112000173 is a prime.

It is a super-2 number, since 2×21121112002221² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21121112002194 and 21121112002203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121112002231) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 71431741 + ... + 71726813.

It is an arithmetic number, because the mean of its divisors is an integer number (792433029960).

Almost surely, 2^{21121112002221} is an apocalyptic number.

21121112002221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21121112002221 is a deficient number, since it is larger than the sum of its proper divisors (16915673435859).

21121112002221 is a wasteful number, since it uses less digits than its factorization.

21121112002221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 398386 (or 398383 counting only the distinct ones).

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

Adding to 21121112002221 its reverse (12220021112112), we get a palindrome (33341133114333).

The spelling of 21121112002221 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred twelve million, two thousand, two hundred twenty-one".