210242021 has 4 divisors (see below), whose sum is σ = 229354944. Its totient is φ = 191129100.

The previous prime is 210242017. The next prime is 210242027. The reversal of 210242021 is 120242012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 210242021 - 2² = 210242017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 210241987 and 210242005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210242027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9556445 + ... + 9556466.

It is an arithmetic number, because the mean of its divisors is an integer number (57338736).

Almost surely, 2^210242021 is an apocalyptic number.

It is an amenable number.

210242021 is a deficient number, since it is larger than the sum of its proper divisors (19112923).

210242021 is a wasteful number, since it uses less digits than its factorization.

210242021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19112922.

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 210242021 is about 14499.7248594585. The cubic root of 210242021 is about 594.6204495070.

Adding to 210242021 its reverse (120242012), we get a palindrome (330484033).

Subtracting from 210242021 its reverse (120242012), we obtain a palindrome (90000009).

The spelling of 210242021 in words is "two hundred ten million, two hundred forty-two thousand, twenty-one".