21424203253525 has 12 divisors (see below), whose sum is σ = 26566097570532. Its totient is φ = 17139307418240.

The previous prime is 21424203253501. The next prime is 21424203253547. The reversal of 21424203253525 is 52535230242412.

It can be written as a sum of positive squares in 6 ways, for example, as 30821664721 + 21393381588804 = 175561^2 + 4625298^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21424203253525 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7716057 + ... + 10118593.

It is an arithmetic number, because the mean of its divisors is an integer number (2213841464211).

Almost surely, 2^{21424203253525} is an apocalyptic number.

21424203253525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21424203253525 is a deficient number, since it is larger than the sum of its proper divisors (5141894317007).

21424203253525 is a wasteful number, since it uses less digits than its factorization.

21424203253525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2759240 (or 2759235 counting only the distinct ones).

The product of its (nonzero) digits is 576000, while the sum is 40.

Adding to 21424203253525 its reverse (52535230242412), we get a palindrome (73959433495937).

The spelling of 21424203253525 in words is "twenty-one trillion, four hundred twenty-four billion, two hundred three million, two hundred fifty-three thousand, five hundred twenty-five".