123815281543 has 4 divisors (see below), whose sum is σ = 128084774040. Its totient is φ = 119545789048.

The previous prime is 123815281517. The next prime is 123815281547. The reversal of 123815281543 is 345182518321.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123815281543 is a prime.

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 123815281543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123815281547) 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, 2134746205 + ... + 2134746262.

It is an arithmetic number, because the mean of its divisors is an integer number (32021193510).

Almost surely, 2^123815281543 is an apocalyptic number.

123815281543 is a deficient number, since it is larger than the sum of its proper divisors (4269492497).

123815281543 is an equidigital number, since it uses as much as digits as its factorization.

123815281543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4269492496.

The product of its digits is 230400, while the sum is 43.

Adding to 123815281543 its reverse (345182518321), we get a palindrome (468997799864).

The spelling of 123815281543 in words is "one hundred twenty-three billion, eight hundred fifteen million, two hundred eighty-one thousand, five hundred forty-three".