21521080325441 has 4 divisors (see below), whose sum is σ = 21521323526832. Its totient is φ = 21520837124052.

The previous prime is 21521080325429. The next prime is 21521080325513. The reversal of 21521080325441 is 14452308012512.

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 21521080325441 - 2³⁴ = 21503900456257 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21521080325395 and 21521080325404.

It is not an unprimeable number, because it can be changed into a prime (21521080321441) 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, 121467911 + ... + 121644956.

It is an arithmetic number, because the mean of its divisors is an integer number (5380330881708).

Almost surely, 2^{21521080325441} is an apocalyptic number.

It is an amenable number.

21521080325441 is a deficient number, since it is larger than the sum of its proper divisors (243201391).

21521080325441 is an equidigital number, since it uses as much as digits as its factorization.

21521080325441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243201390.

The product of its (nonzero) digits is 76800, while the sum is 38.

Adding to 21521080325441 its reverse (14452308012512), we get a palindrome (35973388337953).

The spelling of 21521080325441 in words is "twenty-one trillion, five hundred twenty-one billion, eighty million, three hundred twenty-five thousand, four hundred forty-one".