3646821 has 8 divisors (see below), whose sum is σ = 4876960. Its totient is φ = 2423952.

The previous prime is 3646817. The next prime is 3646829. The reversal of 3646821 is 1286463.

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

It is not a de Polignac number, because 3646821 - 2² = 3646817 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3646829) 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 7 ways as a sum of consecutive naturals, for example, 511 + ... + 2748.

It is an arithmetic number, because the mean of its divisors is an integer number (609620).

Almost surely, 2^3646821 is an apocalyptic number.

It is an amenable number.

3646821 is a deficient number, since it is larger than the sum of its proper divisors (1230139).

3646821 is a wasteful number, since it uses less digits than its factorization.

3646821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3635.

The product of its digits is 6912, while the sum is 30.

The square root of 3646821 is about 1909.6651538948. The cubic root of 3646821 is about 153.9234594626.

The spelling of 3646821 in words is "three million, six hundred forty-six thousand, eight hundred twenty-one".