242543821 has 8 divisors (see below), whose sum is σ = 261330104. Its totient is φ = 223776000.

The previous prime is 242543813. The next prime is 242543831. The reversal of 242543821 is 128345242.

It can be written as a sum of positive squares in 4 ways, for example, as 26894596 + 215649225 = 5186^2 + 14685^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 242543821 - 2³ = 242543813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (242543831) 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 7 ways as a sum of consecutive naturals, for example, 35905 + ... + 42121.

It is an arithmetic number, because the mean of its divisors is an integer number (32666263).

Almost surely, 2^242543821 is an apocalyptic number.

It is an amenable number.

242543821 is a deficient number, since it is larger than the sum of its proper divisors (18786283).

242543821 is a wasteful number, since it uses less digits than its factorization.

242543821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9231.

The product of its digits is 15360, while the sum is 31.

The square root of 242543821 is about 15573.8184463541. The cubic root of 242543821 is about 623.6344123657.

The spelling of 242543821 in words is "two hundred forty-two million, five hundred forty-three thousand, eight hundred twenty-one".