40208821 has 8 divisors (see below), whose sum is σ = 41642424. Its totient is φ = 38800320.

The previous prime is 40208809. The next prime is 40208837. The reversal of 40208821 is 12880204.

40208821 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 342225 + 39866596 = 585^2 + 6314^2 .

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 40208821 - 2⁵ = 40208789 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 (40208221) 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, 2986 + ... + 9451.

It is an arithmetic number, because the mean of its divisors is an integer number (5205303).

Almost surely, 2^40208821 is an apocalyptic number.

It is an amenable number.

40208821 is a deficient number, since it is larger than the sum of its proper divisors (1433603).

40208821 is a wasteful number, since it uses less digits than its factorization.

40208821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12551.

The product of its (nonzero) digits is 1024, while the sum is 25.

The square root of 40208821 is about 6341.0425798917. The cubic root of 40208821 is about 342.5892881742.

The spelling of 40208821 in words is "forty million, two hundred eight thousand, eight hundred twenty-one".