20445213241521 has 24 divisors (see below), whose sum is σ = 30583917588224. Its totient is φ = 13147494432480.

The previous prime is 20445213241513. The next prime is 20445213241543. The reversal of 20445213241521 is 12514231254402.

20445213241521 is a `hidden beast` number, since 2 + 0 + 4 + 4 + 5 + 213 + 2 + 415 + 21 = 666.

It is not a de Polignac number, because 20445213241521 - 2³ = 20445213241513 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20445213241501) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 119263426 + ... + 119434731.

Almost surely, 2^{20445213241521} is an apocalyptic number.

It is an amenable number.

20445213241521 is a deficient number, since it is larger than the sum of its proper divisors (10138704346703).

20445213241521 is a wasteful number, since it uses less digits than its factorization.

20445213241521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238698501 (or 238698498 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 36.

Adding to 20445213241521 its reverse (12514231254402), we get a palindrome (32959444495923).

The spelling of 20445213241521 in words is "twenty trillion, four hundred forty-five billion, two hundred thirteen million, two hundred forty-one thousand, five hundred twenty-one".