121221010111 has 4 divisors (see below), whose sum is σ = 121508946424. Its totient is φ = 120933073800.

The previous prime is 121221010109. The next prime is 121221010117. The reversal of 121221010111 is 111010122121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 111010122121 = 43 ⋅2581630747.

It is a cyclic number.

It is not a de Polignac number, because 121221010111 - 2¹ = 121221010109 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121221010091 and 121221010100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221010117) 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, 143967525 + ... + 143968366.

It is an arithmetic number, because the mean of its divisors is an integer number (30377236606).

Almost surely, 2^121221010111 is an apocalyptic number.

121221010111 is a deficient number, since it is larger than the sum of its proper divisors (287936313).

121221010111 is an equidigital number, since it uses as much as digits as its factorization.

121221010111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287936312.

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

Adding to 121221010111 its reverse (111010122121), we get a palindrome (232231132232).

The spelling of 121221010111 in words is "one hundred twenty-one billion, two hundred twenty-one million, ten thousand, one hundred eleven".