21523544121430 has 16 divisors (see below), whose sum is σ = 41722562451024. Its totient is φ = 7947154752480.

The previous prime is 21523544121383. The next prime is 21523544121437. The reversal of 21523544121430 is 3412144532512.

It is a self number, because there is not a number n which added to its sum of digits gives 21523544121430.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21523544121437) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82782861876 + ... + 82782862135.

It is an arithmetic number, because the mean of its divisors is an integer number (2607660153189).

Almost surely, 2^{21523544121430} is an apocalyptic number.

21523544121430 is a deficient number, since it is larger than the sum of its proper divisors (20199018329594).

21523544121430 is a wasteful number, since it uses less digits than its factorization.

21523544121430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165565724031.

The product of its (nonzero) digits is 115200, while the sum is 37.

Adding to 21523544121430 its reverse (3412144532512), we get a palindrome (24935688653942).

The spelling of 21523544121430 in words is "twenty-one trillion, five hundred twenty-three billion, five hundred forty-four million, one hundred twenty-one thousand, four hundred thirty".