2123201309 has 4 divisors (see below), whose sum is σ = 2126933340. Its totient is φ = 2119469280.

The previous prime is 2123201287. The next prime is 2123201351. The reversal of 2123201309 is 9031023212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1409777209 + 713424100 = 37547^2 + 26710^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2123201309 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 (2123201809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1865162 + ... + 1866299.

It is an arithmetic number, because the mean of its divisors is an integer number (531733335).

Almost surely, 2^2123201309 is an apocalyptic number.

It is an amenable number.

2123201309 is a deficient number, since it is larger than the sum of its proper divisors (3732031).

2123201309 is an equidigital number, since it uses as much as digits as its factorization.

2123201309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3732030.

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

The square root of 2123201309 is about 46078.2086131829. The cubic root of 2123201309 is about 1285.2779524597.

The spelling of 2123201309 in words is "two billion, one hundred twenty-three million, two hundred one thousand, three hundred nine".