123563521823569 has 3 divisors (see below), whose sum is σ = 123563532939483. Its totient is φ = 123563510707656.

The previous prime is 123563521823557. The next prime is 123563521823591. The reversal of 123563521823569 is 965328125365321.

The square root of 123563521823569 is 11115913.

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

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.

It can be written as a sum of positive squares in only one way, i.e., 122955608446225 + 607913377344 = 11088535^2 + 779688^2 .

It is not a de Polignac number, because 123563521823569 - 2⁵ = 123563521823537 is a prime.

It is a super-3 number, since 3×123563521823569³ (a number of 43 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123563521823669) 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, 5557957 + ... + 16673869.

It is an arithmetic number, because the mean of its divisors is an integer number (41187844313161).

Almost surely, 2^{123563521823569} is an apocalyptic number.

123563521823569 is the 11115913-rd square number.

123563521823569 is the 5557957-th centered octagonal number.

It is an amenable number.

123563521823569 is a deficient number, since it is larger than the sum of its proper divisors (11115914).

123563521823569 is an frugal number, since it uses more digits than its factorization.

123563521823569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22231826 (or 11115913 counting only the distinct ones).

The product of its digits is 69984000, while the sum is 61.

It can be divided in two parts, 1235635 and 21823569, that added together give a square (23059204 = 4802²).

The spelling of 123563521823569 in words is "one hundred twenty-three trillion, five hundred sixty-three billion, five hundred twenty-one million, eight hundred twenty-three thousand, five hundred sixty-nine".