21523104455424 has 144 divisors (see below), whose sum is σ = 67297329571584. Its totient is φ = 6020448768000.

The previous prime is 21523104455417. The next prime is 21523104455467. The reversal of 21523104455424 is 42455440132512.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 97879252 + ... + 98098899.

Almost surely, 2^{21523104455424} is an apocalyptic number.

21523104455424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21523104455424 is an abundant number, since it is smaller than the sum of its proper divisors (45774225116160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21523104455424 is a wasteful number, since it uses less digits than its factorization.

21523104455424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195978194 (or 195978180 counting only the distinct ones).

The product of its (nonzero) digits is 768000, while the sum is 42.

Adding to 21523104455424 its reverse (42455440132512), we get a palindrome (63978544587936).

The spelling of 21523104455424 in words is "twenty-one trillion, five hundred twenty-three billion, one hundred four million, four hundred fifty-five thousand, four hundred twenty-four".