12001021 has 2 divisors, whose sum is σ = 12001022. Its totient is φ = 12001020.

The previous prime is 12001001. The next prime is 12001037. The reversal of 12001021 is 12010021.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11978521 + 22500 = 3461^2 + 150^2 .

It is an emirp because it is prime and its reverse (12010021) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12001021 - 2⁹ = 12000509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12000995 and 12001013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12001001) 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 as a sum of consecutive naturals, namely, 6000510 + 6000511.

It is an arithmetic number, because the mean of its divisors is an integer number (6000511).

Almost surely, 2^12001021 is an apocalyptic number.

It is an amenable number.

12001021 is a deficient number, since it is larger than the sum of its proper divisors (1).

12001021 is an equidigital number, since it uses as much as digits as its factorization.

12001021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 12001021 is about 3464.2489806594. The cubic root of 12001021 is about 228.9493414001.

Adding to 12001021 its reverse (12010021), we get a palindrome (24011042).

The spelling of 12001021 in words is "twelve million, one thousand, twenty-one".