21445220541525 has 96 divisors (see below), whose sum is σ = 41110432097280. Its totient is φ = 9754800192000.

The previous prime is 21445220541523. The next prime is 21445220541533. The reversal of 21445220541525 is 52514502254412.

It is not a de Polignac number, because 21445220541525 - 2¹ = 21445220541523 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21445220541523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5026816 + ... + 8255865.

It is an arithmetic number, because the mean of its divisors is an integer number (428233667680).

Almost surely, 2^{21445220541525} is an apocalyptic number.

21445220541525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21445220541525 is a deficient number, since it is larger than the sum of its proper divisors (19665211555755).

21445220541525 is a wasteful number, since it uses less digits than its factorization.

21445220541525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13282827 (or 13282822 counting only the distinct ones).

The product of its (nonzero) digits is 640000, while the sum is 42.

Adding to 21445220541525 its reverse (52514502254412), we get a palindrome (73959722795937).

The spelling of 21445220541525 in words is "twenty-one trillion, four hundred forty-five billion, two hundred twenty million, five hundred forty-one thousand, five hundred twenty-five".