3721805 has 8 divisors (see below), whose sum is σ = 4507800. Its totient is φ = 2949696.

The previous prime is 3721799. The next prime is 3721807. The reversal of 3721805 is 5081273.

3721805 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 687241 + 3034564 = 829^2 + 1742^2 .

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 3721805 - 2⁶ = 3721741 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3721807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2870 + ... + 3959.

It is an arithmetic number, because the mean of its divisors is an integer number (563475).

Almost surely, 2^3721805 is an apocalyptic number.

It is an amenable number.

3721805 is a deficient number, since it is larger than the sum of its proper divisors (785995).

3721805 is a wasteful number, since it uses less digits than its factorization.

3721805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6943.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 3721805 is about 1929.1980199036. The cubic root of 3721805 is about 154.9712745935.

The spelling of 3721805 in words is "three million, seven hundred twenty-one thousand, eight hundred five".