243530261 has 4 divisors (see below), whose sum is σ = 262263372. Its totient is φ = 224797152.

The previous prime is 243530257. The next prime is 243530281. The reversal of 243530261 is 162035342.

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 114276100 + 129254161 = 10690^2 + 11369^2 .

It is a cyclic number.

It is not a de Polignac number, because 243530261 - 2² = 243530257 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 243530261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243530281) 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, 9366536 + ... + 9366561.

It is an arithmetic number, because the mean of its divisors is an integer number (65565843).

Almost surely, 2^243530261 is an apocalyptic number.

It is an amenable number.

243530261 is a deficient number, since it is larger than the sum of its proper divisors (18733111).

243530261 is a wasteful number, since it uses less digits than its factorization.

243530261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18733110.

The product of its (nonzero) digits is 4320, while the sum is 26.

The square root of 243530261 is about 15605.4561291876. The cubic root of 243530261 is about 624.4787214040.

The spelling of 243530261 in words is "two hundred forty-three million, five hundred thirty thousand, two hundred sixty-one".