21503423325 has 12 divisors (see below), whose sum is σ = 35552326688. Its totient is φ = 11468492400.

The previous prime is 21503423323. The next prime is 21503423341. The reversal of 21503423325 is 52332430512.

It is not a de Polignac number, because 21503423325 - 2¹ = 21503423323 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21503423292 and 21503423301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21503423323) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 143356081 + ... + 143356230.

Almost surely, 2^21503423325 is an apocalyptic number.

21503423325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21503423325 is a deficient number, since it is larger than the sum of its proper divisors (14048903363).

21503423325 is a wasteful number, since it uses less digits than its factorization.

21503423325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 286712324 (or 286712319 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 30.

Adding to 21503423325 its reverse (52332430512), we get a palindrome (73835853837).

The spelling of 21503423325 in words is "twenty-one billion, five hundred three million, four hundred twenty-three thousand, three hundred twenty-five".