200001821 has 4 divisors (see below), whose sum is σ = 211766652. Its totient is φ = 188236992.

The previous prime is 200001797. The next prime is 200001827. The reversal of 200001821 is 128100002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 71995225 + 128006596 = 8485^2 + 11314^2 .

It is a cyclic number.

It is not a de Polignac number, because 200001821 - 2⁶ = 200001757 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 200001796 and 200001805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (200001827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5882390 + ... + 5882423.

It is an arithmetic number, because the mean of its divisors is an integer number (52941663).

Almost surely, 2^200001821 is an apocalyptic number.

It is an amenable number.

200001821 is a deficient number, since it is larger than the sum of its proper divisors (11764831).

200001821 is a wasteful number, since it uses less digits than its factorization.

200001821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11764830.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 200001821 is about 14142.2000056568. The cubic root of 200001821 is about 584.8053225160.

Adding to 200001821 its reverse (128100002), we get a palindrome (328101823).

The spelling of 200001821 in words is "two hundred million, one thousand, eight hundred twenty-one".