3243721 has 4 divisors (see below), whose sum is σ = 3493252. Its totient is φ = 2994192.

The previous prime is 3243697. The next prime is 3243727. The reversal of 3243721 is 1273423.

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 404496 + 2839225 = 636^2 + 1685^2 .

It is a cyclic number.

It is not a de Polignac number, because 3243721 - 2¹¹ = 3241673 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3243692 and 3243701.

It is not an unprimeable number, because it can be changed into a prime (3243727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124746 + ... + 124771.

It is an arithmetic number, because the mean of its divisors is an integer number (873313).

Almost surely, 2^3243721 is an apocalyptic number.

It is an amenable number.

3243721 is a deficient number, since it is larger than the sum of its proper divisors (249531).

3243721 is a wasteful number, since it uses less digits than its factorization.

3243721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249530.

The product of its digits is 1008, while the sum is 22.

The square root of 3243721 is about 1801.0333145170. The cubic root of 3243721 is about 148.0293495483.

It can be divided in two parts, 3243 and 721, that multiplied together give a triangular number (2338203 = T₂₁₆₂).

The spelling of 3243721 in words is "three million, two hundred forty-three thousand, seven hundred twenty-one".