12111021 has 24 divisors (see below), whose sum is σ = 19950840. Its totient is φ = 7013376.

The previous prime is 12111019. The next prime is 12111023. The reversal of 12111021 is 12011121.

It is a happy number.

12111021 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (12111019) and next prime (12111023).

It can be written as a sum of positive squares in 4 ways, for example, as 476100 + 11634921 = 690^2 + 3411^2 .

It is not a de Polignac number, because 12111021 - 2¹ = 12111019 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 = 12110994 and 12111012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12111023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1056 + ... + 5033.

It is an arithmetic number, because the mean of its divisors is an integer number (831285).

Almost surely, 2^12111021 is an apocalyptic number.

It is an amenable number.

12111021 is a deficient number, since it is larger than the sum of its proper divisors (7839819).

12111021 is a wasteful number, since it uses less digits than its factorization.

12111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6125 (or 6122 counting only the distinct ones).

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

The square root of 12111021 is about 3480.0892229941. The cubic root of 12111021 is about 229.6467229291.

Adding to 12111021 its reverse (12011121), we get a palindrome (24122142).

The spelling of 12111021 in words is "twelve million, one hundred eleven thousand, twenty-one".