243481553 has 4 divisors (see below), whose sum is σ = 278264640. Its totient is φ = 208698468.

The previous prime is 243481547. The next prime is 243481583. The reversal of 243481553 is 355184342.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 243481553 - 2²⁰ = 242432977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243481583) 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, 17391533 + ... + 17391546.

It is an arithmetic number, because the mean of its divisors is an integer number (69566160).

Almost surely, 2^243481553 is an apocalyptic number.

It is an amenable number.

243481553 is a deficient number, since it is larger than the sum of its proper divisors (34783087).

243481553 is an equidigital number, since it uses as much as digits as its factorization.

243481553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34783086.

The product of its digits is 57600, while the sum is 35.

The square root of 243481553 is about 15603.8954431257. The cubic root of 243481553 is about 624.4370850484.

The spelling of 243481553 in words is "two hundred forty-three million, four hundred eighty-one thousand, five hundred fifty-three".