404285821 has 2 divisors, whose sum is σ = 404285822. Its totient is φ = 404285820.

The previous prime is 404285807. The next prime is 404285867. The reversal of 404285821 is 128582404.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 397204900 + 7080921 = 19930^2 + 2661^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-404285821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (404285221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202142910 + 202142911.

It is an arithmetic number, because the mean of its divisors is an integer number (202142911).

Almost surely, 2^404285821 is an apocalyptic number.

It is an amenable number.

404285821 is a deficient number, since it is larger than the sum of its proper divisors (1).

404285821 is an equidigital number, since it uses as much as digits as its factorization.

404285821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20480, while the sum is 34.

The square root of 404285821 is about 20106.8600482522. The cubic root of 404285821 is about 739.4284733625.

It can be divided in two parts, 404 and 285821, that added together give a square (286225 = 535²).

The spelling of 404285821 in words is "four hundred four million, two hundred eighty-five thousand, eight hundred twenty-one".