210442821 has 8 divisors (see below), whose sum is σ = 290266080. Its totient is φ = 135457392.

The previous prime is 210442819. The next prime is 210442853. The reversal of 210442821 is 128244012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 210442821 - 2¹ = 210442819 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 210442791 and 210442800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210442021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1209355 + ... + 1209528.

It is an arithmetic number, because the mean of its divisors is an integer number (36283260).

Almost surely, 2^210442821 is an apocalyptic number.

It is an amenable number.

210442821 is a deficient number, since it is larger than the sum of its proper divisors (79823259).

210442821 is a wasteful number, since it uses less digits than its factorization.

210442821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2418915.

The product of its (nonzero) digits is 1024, while the sum is 24.

The square root of 210442821 is about 14506.6474762434. The cubic root of 210442821 is about 594.8096945706.

Adding to 210442821 its reverse (128244012), we get a palindrome (338686833).

The spelling of 210442821 in words is "two hundred ten million, four hundred forty-two thousand, eight hundred twenty-one".