243391201 has 3 divisors (see below), whose sum is σ = 243406803. Its totient is φ = 243375600.

The previous prime is 243391157. The next prime is 243391219. The reversal of 243391201 is 102193342.

The square root of 243391201 is 15601.

It is a perfect power (a square), and thus also a powerful number.

243391201 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 102193342 = 2 ⋅51096671.

It can be written as a sum of positive squares in only one way, i.e., 229552801 + 13838400 = 15151^2 + 3720^2 .

It is not a de Polignac number, because 243391201 - 2⁷ = 243391073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243391801) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 7801 + ... + 23401.

It is an arithmetic number, because the mean of its divisors is an integer number (81135601).

Almost surely, 2^243391201 is an apocalyptic number.

243391201 is the 15601-st square number.

243391201 is the 7801-st centered octagonal number.

It is an amenable number.

243391201 is a deficient number, since it is larger than the sum of its proper divisors (15602).

243391201 is an frugal number, since it uses more digits than its factorization.

243391201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31202 (or 15601 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The cubic root of 243391201 is about 624.3598360481.

Multiplying 243391201 by its sum of digits (25), we get a square (6084780025 = 78005²).

Multiplying 243391201 by its product of nonzero digits (1296), we get a square (315434996496 = 561636²).

The spelling of 243391201 in words is "two hundred forty-three million, three hundred ninety-one thousand, two hundred one".