2121402321 has 6 divisors (see below), whose sum is σ = 3064247810. Its totient is φ = 1414268208.

The previous prime is 2121402313. The next prime is 2121402329. The reversal of 2121402321 is 1232041212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (2121402313) and next prime (2121402329).

It can be written as a sum of positive squares in only one way, i.e., 1229484096 + 891918225 = 35064^2 + 29865^2 .

It is not a de Polignac number, because 2121402321 - 2³ = 2121402313 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121402294 and 2121402303.

It is not an unprimeable number, because it can be changed into a prime (2121402329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 117855676 + ... + 117855693.

Almost surely, 2^2121402321 is an apocalyptic number.

It is an amenable number.

2121402321 is a deficient number, since it is larger than the sum of its proper divisors (942845489).

2121402321 is a wasteful number, since it uses less digits than its factorization.

2121402321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235711375 (or 235711372 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 2121402321 is about 46058.6834484009. The cubic root of 2121402321 is about 1284.9148446449.

Adding to 2121402321 its reverse (1232041212), we get a palindrome (3353443533).

The spelling of 2121402321 in words is "two billion, one hundred twenty-one million, four hundred two thousand, three hundred twenty-one".