242821001 has 4 divisors (see below), whose sum is σ = 242989572. Its totient is φ = 242652432.

The previous prime is 242820989. The next prime is 242821021. The reversal of 242821001 is 100128242.

It is a happy number.

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 214476025 + 28344976 = 14645^2 + 5324^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-242821001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (242821021) 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, 82106 + ... + 85011.

It is an arithmetic number, because the mean of its divisors is an integer number (60747393).

Almost surely, 2^242821001 is an apocalyptic number.

It is an amenable number.

242821001 is a deficient number, since it is larger than the sum of its proper divisors (168571).

242821001 is a wasteful number, since it uses less digits than its factorization.

242821001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168570.

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 242821001 is about 15582.7148148197. The cubic root of 242821001 is about 623.8718858520.

Adding to 242821001 its reverse (100128242), we get a palindrome (342949243).

The spelling of 242821001 in words is "two hundred forty-two million, eight hundred twenty-one thousand, one".