121211111021 has 128 divisors (see below), whose sum is σ = 176532787200. Its totient is φ = 80583310080.

The previous prime is 121211111017. The next prime is 121211111029. The reversal of 121211111021 is 120111112121.

It is not a de Polignac number, because 121211111021 - 2² = 121211111017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 121211110987 and 121211111005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121211111029) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 138210635 + ... + 138211511.

It is an arithmetic number, because the mean of its divisors is an integer number (1379162400).

Almost surely, 2^121211111021 is an apocalyptic number.

121211111021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121211111021 is a deficient number, since it is larger than the sum of its proper divisors (55321676179).

121211111021 is a wasteful number, since it uses less digits than its factorization.

121211111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 996 (or 970 counting only the distinct ones).

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

Adding to 121211111021 its reverse (120111112121), we get a palindrome (241322223142).

It can be divided in two parts, 121211 and 111021, that added together give a palindrome (232232).

The spelling of 121211111021 in words is "one hundred twenty-one billion, two hundred eleven million, one hundred eleven thousand, twenty-one".