242210021 has 4 divisors (see below), whose sum is σ = 243110700. Its totient is φ = 241309344.

The previous prime is 242209997. The next prime is 242210041. The reversal of 242210021 is 120012242.

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 137147521 + 105062500 = 11711^2 + 10250^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-242210021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 242209978 and 242210005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (242210041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 449936 + ... + 450473.

It is an arithmetic number, because the mean of its divisors is an integer number (60777675).

Almost surely, 2^242210021 is an apocalyptic number.

It is an amenable number.

242210021 is a deficient number, since it is larger than the sum of its proper divisors (900679).

242210021 is an equidigital number, since it uses as much as digits as its factorization.

242210021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 900678.

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

The square root of 242210021 is about 15563.0980527657. The cubic root of 242210021 is about 623.3481895347.

Adding to 242210021 its reverse (120012242), we get a palindrome (362222263).

The spelling of 242210021 in words is "two hundred forty-two million, two hundred ten thousand, twenty-one".