21021112112121 has 48 divisors (see below), whose sum is σ = 33263613871488. Its totient is φ = 12686469734400.

The previous prime is 21021112112113. The next prime is 21021112112123. The reversal of 21021112112121 is 12121121112012.

It is a happy number.

21021112112121 is a `hidden beast` number, since 210 + 21 + 11 + 211 + 212 + 1 = 666.

It is not a de Polignac number, because 21021112112121 - 2³ = 21021112112113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21021112112094 and 21021112112103.

It is not an unprimeable number, because it can be changed into a prime (21021112112123) 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, 81059155 + ... + 81318071.

It is an arithmetic number, because the mean of its divisors is an integer number (692991955656).

Almost surely, 2^{21021112112121} is an apocalyptic number.

It is an amenable number.

21021112112121 is a deficient number, since it is larger than the sum of its proper divisors (12242501759367).

21021112112121 is a wasteful number, since it uses less digits than its factorization.

21021112112121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262382 (or 262379 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 21021112112121 its reverse (12121121112012), we get a palindrome (33142233224133).

The spelling of 21021112112121 in words is "twenty-one trillion, twenty-one billion, one hundred twelve million, one hundred twelve thousand, one hundred twenty-one".