2121001321 has 4 divisors (see below), whose sum is σ = 2142867412. Its totient is φ = 2099135232.

The previous prime is 2121001303. The next prime is 2121001343. The reversal of 2121001321 is 1231001212.

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 1310802025 + 810199296 = 36205^2 + 28464^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121001321 - 2⁷ = 2121001193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2121001301) 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, 10932900 + ... + 10933093.

It is an arithmetic number, because the mean of its divisors is an integer number (535716853).

Almost surely, 2^2121001321 is an apocalyptic number.

It is an amenable number.

2121001321 is a deficient number, since it is larger than the sum of its proper divisors (21866091).

2121001321 is an equidigital number, since it uses as much as digits as its factorization.

2121001321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21866090.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 2121001321 is about 46054.3301004368. The cubic root of 2121001321 is about 1284.8338788114.

Adding to 2121001321 its reverse (1231001212), we get a palindrome (3352002533).

The spelling of 2121001321 in words is "two billion, one hundred twenty-one million, one thousand, three hundred twenty-one".