21445014522521 has 4 divisors (see below), whose sum is σ = 21448535299344. Its totient is φ = 21441493745700.

The previous prime is 21445014522469. The next prime is 21445014522539. The reversal of 21445014522521 is 12522541054412.

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 a de Polignac number, because none of the positive numbers 2^k-21445014522521 is a prime.

It is a super-2 number, since 2×21445014522521² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21445014522541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1760379275 + ... + 1760391456.

It is an arithmetic number, because the mean of its divisors is an integer number (5362133824836).

Almost surely, 2^{21445014522521} is an apocalyptic number.

It is an amenable number.

21445014522521 is a deficient number, since it is larger than the sum of its proper divisors (3520776823).

21445014522521 is an equidigital number, since it uses as much as digits as its factorization.

21445014522521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3520776822.

The product of its (nonzero) digits is 128000, while the sum is 38.

Adding to 21445014522521 its reverse (12522541054412), we get a palindrome (33967555576933).

The spelling of 21445014522521 in words is "twenty-one trillion, four hundred forty-five billion, fourteen million, five hundred twenty-two thousand, five hundred twenty-one".