243426521 has 8 divisors (see below), whose sum is σ = 264473160. Its totient is φ = 222711552.

The previous prime is 243426511. The next prime is 243426529. The reversal of 243426521 is 125624342.

It can be written as a sum of positive squares in 4 ways, for example, as 409600 + 243016921 = 640^2 + 15589^2 .

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 243426521 - 2¹⁸ = 243164377 is a prime.

It is a super-2 number, since 2×243426521² = 118512942252326882, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (243426529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81386 + ... + 84323.

It is an arithmetic number, because the mean of its divisors is an integer number (33059145).

Almost surely, 2^243426521 is an apocalyptic number.

It is an amenable number.

243426521 is a deficient number, since it is larger than the sum of its proper divisors (21046639).

243426521 is a wasteful number, since it uses less digits than its factorization.

243426521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165835.

The product of its digits is 11520, while the sum is 29.

The square root of 243426521 is about 15602.1319376552. The cubic root of 243426521 is about 624.3900361576.

The spelling of 243426521 in words is "two hundred forty-three million, four hundred twenty-six thousand, five hundred twenty-one".