21111133113121 has 8 divisors (see below), whose sum is σ = 21839294503080. Its totient is φ = 20382984475392.

The previous prime is 21111133113113. The next prime is 21111133113173. The reversal of 21111133113121 is 12131133111112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3025982016225 + 18085151096896 = 1739535^2 + 4252664^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21111133113121 - 2³ = 21111133113113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111133113092 and 21111133113101.

It is not an unprimeable number, because it can be changed into a prime (21111133113821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 242601 + ... + 6502393.

It is an arithmetic number, because the mean of its divisors is an integer number (2729911812885).

Almost surely, 2^{21111133113121} is an apocalyptic number.

It is an amenable number.

21111133113121 is a deficient number, since it is larger than the sum of its proper divisors (728161389959).

21111133113121 is a wasteful number, since it uses less digits than its factorization.

21111133113121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6376115.

The product of its digits is 108, while the sum is 22.

Adding to 21111133113121 its reverse (12131133111112), we get a palindrome (33242266224233).

The spelling of 21111133113121 in words is "twenty-one trillion, one hundred eleven billion, one hundred thirty-three million, one hundred thirteen thousand, one hundred twenty-one".