3709821 has 8 divisors (see below), whose sum is σ = 5016384. Its totient is φ = 2438240.

The previous prime is 3709819. The next prime is 3709829. The reversal of 3709821 is 1289073.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 3709821 - 2¹ = 3709819 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3709829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8496 + ... + 8921.

It is an arithmetic number, because the mean of its divisors is an integer number (627048).

Almost surely, 2^3709821 is an apocalyptic number.

It is an amenable number.

3709821 is a deficient number, since it is larger than the sum of its proper divisors (1306563).

3709821 is a wasteful number, since it uses less digits than its factorization.

3709821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17491.

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 3709821 is about 1926.0895617806. The cubic root of 3709821 is about 154.8047628551.

The spelling of 3709821 in words is "three million, seven hundred nine thousand, eight hundred twenty-one".