21121220011121 has 8 divisors (see below), whose sum is σ = 22110400600704. Its totient is φ = 20137944977920.

The previous prime is 21121220011079. The next prime is 21121220011141. The reversal of 21121220011121 is 12111002212112.

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 21121220011121 - 2³⁰ = 21120146269297 is a prime.

It is a super-2 number, since 2×21121220011121² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21121220011121.

It is not an unprimeable number, because it can be changed into a prime (21121220011141) 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, 1476381776 + ... + 1476396081.

It is an arithmetic number, because the mean of its divisors is an integer number (2763800075088).

Almost surely, 2^{21121220011121} is an apocalyptic number.

It is an amenable number.

21121220011121 is a deficient number, since it is larger than the sum of its proper divisors (989180589583).

21121220011121 is a wasteful number, since it uses less digits than its factorization.

21121220011121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2952778191.

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

Adding to 21121220011121 its reverse (12111002212112), we get a palindrome (33232222223233).

The spelling of 21121220011121 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twenty million, eleven thousand, one hundred twenty-one".