210121121111 has 12 divisors (see below), whose sum is σ = 238409892672. Its totient is φ = 184857288000.

The previous prime is 210121121083. The next prime is 210121121117. The reversal of 210121121111 is 111121121012.

It is a de Polignac number, because none of the positive numbers 2^k-210121121111 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210121121117) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28004930 + ... + 28012431.

It is an arithmetic number, because the mean of its divisors is an integer number (19867491056).

Almost surely, 2^210121121111 is an apocalyptic number.

210121121111 is a deficient number, since it is larger than the sum of its proper divisors (28288771561).

210121121111 is a wasteful number, since it uses less digits than its factorization.

210121121111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56017414 (or 56017403 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 210121121111 its reverse (111121121012), we get a palindrome (321242242123).

Subtracting from 210121121111 its reverse (111121121012), we obtain a palindrome (99000000099).

The spelling of 210121121111 in words is "two hundred ten billion, one hundred twenty-one million, one hundred twenty-one thousand, one hundred eleven".