121111120021 has 4 divisors (see below), whose sum is σ = 121194473932. Its totient is φ = 121027766112.

The previous prime is 121111120003. The next prime is 121111120049. The reversal of 121111120021 is 120021111121.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 118959459025 + 2151660996 = 344905^2 + 46386^2 .

It is a cyclic number.

It is not a de Polignac number, because 121111120021 - 2¹⁹ = 121110595733 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121111119983 and 121111120010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121111120321) 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, 41674776 + ... + 41677681.

It is an arithmetic number, because the mean of its divisors is an integer number (30298618483).

Almost surely, 2^121111120021 is an apocalyptic number.

It is an amenable number.

121111120021 is a deficient number, since it is larger than the sum of its proper divisors (83353911).

121111120021 is an equidigital number, since it uses as much as digits as its factorization.

121111120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83353910.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 121111120021 its reverse (120021111121), we get a palindrome (241132231142).

The spelling of 121111120021 in words is "one hundred twenty-one billion, one hundred eleven million, one hundred twenty thousand, twenty-one".