243564261 has 8 divisors (see below), whose sum is σ = 325039104. Its totient is φ = 162232800.

The previous prime is 243564257. The next prime is 243564289. The reversal of 243564261 is 162465342.

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

It is not a de Polignac number, because 243564261 - 2² = 243564257 is a prime.

It is a super-2 number, since 2×243564261² = 118647098472952242, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243565261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31816 + ... + 38721.

It is an arithmetic number, because the mean of its divisors is an integer number (40629888).

Almost surely, 2^243564261 is an apocalyptic number.

It is an amenable number.

243564261 is a deficient number, since it is larger than the sum of its proper divisors (81474843).

243564261 is a wasteful number, since it uses less digits than its factorization.

243564261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71691.

The product of its digits is 34560, while the sum is 33.

The square root of 243564261 is about 15606.5454537511. The cubic root of 243564261 is about 624.5077818425.

The spelling of 243564261 in words is "two hundred forty-three million, five hundred sixty-four thousand, two hundred sixty-one".