12106921 has 2 divisors, whose sum is σ = 12106922. Its totient is φ = 12106920.

The previous prime is 12106903. The next prime is 12106973. The reversal of 12106921 is 12960121.

It is the 1421-st star number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8643600 + 3463321 = 2940^2 + 1861^2 .

It is a cyclic number.

It is not a de Polignac number, because 12106921 - 2⁷ = 12106793 is a prime.

It is a super-2 number, since 2×12106921² = 293155072200482, which contains 22 as substring.

It is a Chen prime.

It is the 3480-th Hogben number.

It is a junction number, because it is equal to n+sod(n) for n = 12106892 and 12106901.

It is not a weakly prime, because it can be changed into another prime (12106981) by changing a digit.

It is a nontrivial repunit in base 3479.

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 as a sum of consecutive naturals, namely, 6053460 + 6053461.

It is an arithmetic number, because the mean of its divisors is an integer number (6053461).

Almost surely, 2^12106921 is an apocalyptic number.

It is an amenable number.

12106921 is a deficient number, since it is larger than the sum of its proper divisors (1).

12106921 is an equidigital number, since it uses as much as digits as its factorization.

12106921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 22.

The square root of 12106921 is about 3479.5001077741. The cubic root of 12106921 is about 229.6208055482.

The spelling of 12106921 in words is "twelve million, one hundred six thousand, nine hundred twenty-one".