2021011309 has 4 divisors (see below), whose sum is σ = 2068011616. Its totient is φ = 1974011004.

The previous prime is 2021011297. The next prime is 2021011337. The reversal of 2021011309 is 9031101202.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2021011309 - 2²³ = 2012622701 is a prime.

It is a super-2 number, since 2×2021011309² = 8168973422211786962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021011339) 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 3 ways as a sum of consecutive naturals, for example, 23500089 + ... + 23500174.

It is an arithmetic number, because the mean of its divisors is an integer number (517002904).

Almost surely, 2^2021011309 is an apocalyptic number.

It is an amenable number.

2021011309 is a deficient number, since it is larger than the sum of its proper divisors (47000307).

2021011309 is an equidigital number, since it uses as much as digits as its factorization.

2021011309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47000306.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 2021011309 is about 44955.6593656461. The cubic root of 2021011309 is about 1264.3177872008.

The spelling of 2021011309 in words is "two billion, twenty-one million, eleven thousand, three hundred nine".