21121110202121 has 8 divisors (see below), whose sum is σ = 22233127552320. Its totient is φ = 20009130849072.

The previous prime is 21121110202067. The next prime is 21121110202139. The reversal of 21121110202121 is 12120201112112.

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 21121110202121 - 2⁶ = 21121110202057 is a prime.

It is a super-2 number, since 2×21121110202121² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21121110202121.

It is not an unprimeable number, because it can be changed into a prime (21121110202021) 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, 8354765 + ... + 10585098.

It is an arithmetic number, because the mean of its divisors is an integer number (2779140944040).

Almost surely, 2^{21121110202121} is an apocalyptic number.

It is an amenable number.

21121110202121 is a deficient number, since it is larger than the sum of its proper divisors (1112017350199).

21121110202121 is a wasteful number, since it uses less digits than its factorization.

21121110202121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18998575.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21121110202121 its reverse (12120201112112), we get a palindrome (33241311314233).

Subtracting from 21121110202121 its reverse (12120201112112), we obtain a palindrome (9000909090009).

The spelling of 21121110202121 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred ten million, two hundred two thousand, one hundred twenty-one".