12021009 has 32 divisors (see below), whose sum is σ = 21525504. Its totient is φ = 5762880.

The previous prime is 12021007. The next prime is 12021013. The reversal of 12021009 is 90012021.

It is a happy number.

It is not a de Polignac number, because 12021009 - 2¹ = 12021007 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12021001) 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 31 ways as a sum of consecutive naturals, for example, 1002 + ... + 5004.

It is an arithmetic number, because the mean of its divisors is an integer number (672672).

Almost surely, 2^12021009 is an apocalyptic number.

It is an amenable number.

12021009 is a deficient number, since it is larger than the sum of its proper divisors (9504495).

12021009 is a wasteful number, since it uses less digits than its factorization.

12021009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4037.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 12021009 is about 3467.1326770114. The cubic root of 12021009 is about 229.0763778461.

It can be divided in two parts, 1202 and 1009, that added together give a triangular number (2211 = T₆₆).

The spelling of 12021009 in words is "twelve million, twenty-one thousand, nine".