21120350525 has 6 divisors (see below), whose sum is σ = 26189234682. Its totient is φ = 16896280400.

The previous prime is 21120350443. The next prime is 21120350527. The reversal of 21120350525 is 52505302112.

It can be written as a sum of positive squares in 3 ways, for example, as 1357332964 + 19763017561 = 36842^2 + 140581^2 .

It is not a de Polignac number, because 21120350525 - 2⁸ = 21120350269 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21120350494 and 21120350503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120350527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 422406986 + ... + 422407035.

It is an arithmetic number, because the mean of its divisors is an integer number (4364872447).

Almost surely, 2^21120350525 is an apocalyptic number.

21120350525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21120350525 is a deficient number, since it is larger than the sum of its proper divisors (5068884157).

21120350525 is an equidigital number, since it uses as much as digits as its factorization.

21120350525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 844814031 (or 844814026 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 26.

Adding to 21120350525 its reverse (52505302112), we get a palindrome (73625652637).

The spelling of 21120350525 in words is "twenty-one billion, one hundred twenty million, three hundred fifty thousand, five hundred twenty-five".