21121102202111 has 4 divisors (see below), whose sum is σ = 21214146705432. Its totient is φ = 21028057698792.

The previous prime is 21121102202099. The next prime is 21121102202173. The reversal of 21121102202111 is 11120220112112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21121102202111 is a prime.

It is a super-2 number, since 2×21121102202111² (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 21121102202111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121102252111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46522251320 + ... + 46522251773.

It is an arithmetic number, because the mean of its divisors is an integer number (5303536676358).

Almost surely, 2^{21121102202111} is an apocalyptic number.

21121102202111 is a deficient number, since it is larger than the sum of its proper divisors (93044503321).

21121102202111 is an equidigital number, since it uses as much as digits as its factorization.

21121102202111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93044503320.

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

Adding to 21121102202111 its reverse (11120220112112), we get a palindrome (32241322314223).

The spelling of 21121102202111 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred two million, two hundred two thousand, one hundred eleven".