40004821 has 2 divisors, whose sum is σ = 40004822. Its totient is φ = 40004820.

The previous prime is 40004813. The next prime is 40004827. The reversal of 40004821 is 12840004.

40004821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35640900 + 4363921 = 5970^2 + 2089^2 .

It is a cyclic number.

It is not a de Polignac number, because 40004821 - 2³ = 40004813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40004827) 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 as a sum of consecutive naturals, namely, 20002410 + 20002411.

It is an arithmetic number, because the mean of its divisors is an integer number (20002411).

Almost surely, 2^40004821 is an apocalyptic number.

It is an amenable number.

40004821 is a deficient number, since it is larger than the sum of its proper divisors (1).

40004821 is an equidigital number, since it uses as much as digits as its factorization.

40004821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 40004821 is about 6324.9364423684. The cubic root of 40004821 is about 342.0089284401.

Adding to 40004821 its reverse (12840004), we get a palindrome (52844825).

The spelling of 40004821 in words is "forty million, four thousand, eight hundred twenty-one".