3940821 has 24 divisors (see below), whose sum is σ = 6177600. Its totient is φ = 2411136.

The previous prime is 3940801. The next prime is 3940823. The reversal of 3940821 is 1280493.

3940821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 3940821 - 2⁷ = 3940693 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3940823) 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 23 ways as a sum of consecutive naturals, for example, 6280 + ... + 6878.

It is an arithmetic number, because the mean of its divisors is an integer number (257400).

Almost surely, 2^3940821 is an apocalyptic number.

It is an amenable number.

3940821 is a deficient number, since it is larger than the sum of its proper divisors (2236779).

3940821 is a wasteful number, since it uses less digits than its factorization.

3940821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 665 (or 662 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 3940821 is about 1985.1501202680. The cubic root of 3940821 is about 157.9533724505.

It can be divided in two parts, 3940 and 821, that added together give a square (4761 = 69²).

The spelling of 3940821 in words is "three million, nine hundred forty thousand, eight hundred twenty-one".