2021321309 has 16 divisors (see below), whose sum is σ = 2344760448. Its totient is φ = 1706614272.

The previous prime is 2021321299. The next prime is 2021321333. The reversal of 2021321309 is 9031231202.

It is a cyclic number.

It is not a de Polignac number, because 2021321309 - 2⁴ = 2021321293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021321209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 481829 + ... + 486005.

It is an arithmetic number, because the mean of its divisors is an integer number (146547528).

Almost surely, 2^2021321309 is an apocalyptic number.

It is an amenable number.

2021321309 is a deficient number, since it is larger than the sum of its proper divisors (323439139).

2021321309 is an equidigital number, since it uses as much as digits as its factorization.

2021321309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5204.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 2021321309 is about 44959.1070752078. The cubic root of 2021321309 is about 1264.3824278545.

The spelling of 2021321309 in words is "two billion, twenty-one million, three hundred twenty-one thousand, three hundred nine".