12111021021 has 16 divisors (see below), whose sum is σ = 18543191040. Its totient is φ = 6953695920.

The previous prime is 12111021011. The next prime is 12111021029. The reversal of 12111021021 is 12012011121.

It is not a de Polignac number, because 12111021021 - 2⁵ = 12111020989 is a prime.

It is a super-2 number, since 2×12111021021² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 12111020988 and 12111021006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12111021029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9657285 + ... + 9658538.

It is an arithmetic number, because the mean of its divisors is an integer number (1158949440).

Almost surely, 2^12111021021 is an apocalyptic number.

12111021021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12111021021 is a deficient number, since it is larger than the sum of its proper divisors (6432170019).

12111021021 is a wasteful number, since it uses less digits than its factorization.

12111021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19315856.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 12111021021 its reverse (12012011121), we get a palindrome (24123032142).

The spelling of 12111021021 in words is "twelve billion, one hundred eleven million, twenty-one thousand, twenty-one".