121110021 has 12 divisors (see below), whose sum is σ = 175095648. Its totient is φ = 80666664.

The previous prime is 121109959. The next prime is 121110037. The reversal of 121110021 is 120011121.

It is a happy number.

It is not a de Polignac number, because 121110021 - 2¹⁹ = 120585733 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 121109985 and 121110012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121110721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5506 + ... + 16508.

It is an arithmetic number, because the mean of its divisors is an integer number (14591304).

Almost surely, 2^121110021 is an apocalyptic number.

It is an amenable number.

121110021 is a deficient number, since it is larger than the sum of its proper divisors (53985627).

121110021 is a wasteful number, since it uses less digits than its factorization.

121110021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12232 (or 12229 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 121110021 is about 11004.9998182644. Note that the first 3 decimals coincide. The cubic root of 121110021 is about 494.7586089633.

Adding to 121110021 its reverse (120011121), we get a palindrome (241121142).

It can be divided in two parts, 1211100 and 21, that added together give a palindrome (1211121).

The spelling of 121110021 in words is "one hundred twenty-one million, one hundred ten thousand, twenty-one".