2121342321 has 16 divisors (see below), whose sum is σ = 3301300224. Its totient is φ = 1186403664.

The previous prime is 2121342319. The next prime is 2121342329. The reversal of 2121342321 is 1232431212.

It is not a de Polignac number, because 2121342321 - 2¹ = 2121342319 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2121342329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1073655 + ... + 1075628.

It is an arithmetic number, because the mean of its divisors is an integer number (206331264).

Almost surely, 2^2121342321 is an apocalyptic number.

2121342321 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2121342321 is a deficient number, since it is larger than the sum of its proper divisors (1179957903).

2121342321 is a wasteful number, since it uses less digits than its factorization.

2121342321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2149340.

The product of its digits is 576, while the sum is 21.

The square root of 2121342321 is about 46058.0321008182. The cubic root of 2121342321 is about 1284.9027307055.

Adding to 2121342321 its reverse (1232431212), we get a palindrome (3353773533).

The spelling of 2121342321 in words is "two billion, one hundred twenty-one million, three hundred forty-two thousand, three hundred twenty-one".