4079821 has 2 divisors, whose sum is σ = 4079822. Its totient is φ = 4079820.

The previous prime is 4079819. The next prime is 4079837. The reversal of 4079821 is 1289704.

4079821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2673225 + 1406596 = 1635^2 + 1186^2 .

It is a cyclic number.

It is not a de Polignac number, because 4079821 - 2¹ = 4079819 is a prime.

Together with 4079819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4079861) 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 as a sum of consecutive naturals, namely, 2039910 + 2039911.

It is an arithmetic number, because the mean of its divisors is an integer number (2039911).

Almost surely, 2^4079821 is an apocalyptic number.

It is an amenable number.

4079821 is a deficient number, since it is larger than the sum of its proper divisors (1).

4079821 is an equidigital number, since it uses as much as digits as its factorization.

4079821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 4079821 is about 2019.8566780839. The cubic root of 4079821 is about 159.7890579563.

It can be divided in two parts, 4079 and 821, that added together give a square (4900 = 70²).

The spelling of 4079821 in words is "four million, seventy-nine thousand, eight hundred twenty-one".