243212021155 has 4 divisors (see below), whose sum is σ = 291854425392. Its totient is φ = 194569616920.

The previous prime is 243212021147. The next prime is 243212021191. The reversal of 243212021155 is 551120212342.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 243212021155 - 2³ = 243212021147 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 24321202111 + ... + 24321202120.

It is an arithmetic number, because the mean of its divisors is an integer number (72963606348).

Almost surely, 2^243212021155 is an apocalyptic number.

243212021155 is a deficient number, since it is larger than the sum of its proper divisors (48642404237).

243212021155 is an equidigital number, since it uses as much as digits as its factorization.

243212021155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48642404236.

The product of its (nonzero) digits is 4800, while the sum is 28.

Adding to 243212021155 its reverse (551120212342), we get a palindrome (794332233497).

The spelling of 243212021155 in words is "two hundred forty-three billion, two hundred twelve million, twenty-one thousand, one hundred fifty-five".