2121312309 has 24 divisors (see below), whose sum is σ = 3008501760. Its totient is φ = 1329283584.

The previous prime is 2121312307. The next prime is 2121312311. The reversal of 2121312309 is 9032131212.

2121312309 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (2121312307) and next prime (2121312311).

It is not a de Polignac number, because 2121312309 - 2¹ = 2121312307 is a prime.

It is a super-2 number, since 2×2121312309² = 8999931824629822962, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121312307) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1107937 + ... + 1109849.

It is an arithmetic number, because the mean of its divisors is an integer number (125354240).

Almost surely, 2^2121312309 is an apocalyptic number.

It is an amenable number.

2121312309 is a deficient number, since it is larger than the sum of its proper divisors (887189451).

2121312309 is a wasteful number, since it uses less digits than its factorization.

2121312309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3229 (or 3212 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 2121312309 is about 46057.7062933012. The cubic root of 2121312309 is about 1284.8966712273.

The spelling of 2121312309 in words is "two billion, one hundred twenty-one million, three hundred twelve thousand, three hundred nine".