2021021309 has 8 divisors (see below), whose sum is σ = 2033610432. Its totient is φ = 2008454400.

The previous prime is 2021021269. The next prime is 2021021311. The reversal of 2021021309 is 9031201202.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2021021309 - 2⁸ = 2021021053 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021021329) 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 7 ways as a sum of consecutive naturals, for example, 200234 + ... + 210084.

It is an arithmetic number, because the mean of its divisors is an integer number (254201304).

Almost surely, 2^2021021309 is an apocalyptic number.

It is an amenable number.

2021021309 is a deficient number, since it is larger than the sum of its proper divisors (12589123).

2021021309 is a wasteful number, since it uses less digits than its factorization.

2021021309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11107.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 2021021309 is about 44955.7705862106. The cubic root of 2021021309 is about 1264.3198724864.

The spelling of 2021021309 in words is "two billion, twenty-one million, twenty-one thousand, three hundred nine".