243213101 has 4 divisors (see below), whose sum is σ = 257519772. Its totient is φ = 228906432.

The previous prime is 243213079. The next prime is 243213119. The reversal of 243213101 is 101312342.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 101312342 = 2 ⋅50656171.

It can be written as a sum of positive squares in 2 ways, for example, as 76545001 + 166668100 = 8749^2 + 12910^2 .

It is a cyclic number.

It is not a de Polignac number, because 243213101 - 2⁶ = 243213037 is a prime.

It is a super-2 number, since 2×243213101² = 118305224996072402, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 14306653 = 243213101 / (2 + 4 + 3 + 2 + 1 + 3 + 1 + 0 + 1).

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 243213101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243213121) 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 3 ways as a sum of consecutive naturals, for example, 7153310 + ... + 7153343.

It is an arithmetic number, because the mean of its divisors is an integer number (64379943).

Almost surely, 2^243213101 is an apocalyptic number.

It is an amenable number.

243213101 is a deficient number, since it is larger than the sum of its proper divisors (14306671).

243213101 is a wasteful number, since it uses less digits than its factorization.

243213101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14306670.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 243213101 is about 15595.2909879874. The cubic root of 243213101 is about 624.2075084094.

Adding to 243213101 its reverse (101312342), we get a palindrome (344525443).

The spelling of 243213101 in words is "two hundred forty-three million, two hundred thirteen thousand, one hundred one".