21531103325 has 12 divisors (see below), whose sum is σ = 26700606900. Its totient is φ = 17223567360.

The previous prime is 21531103261. The next prime is 21531103361. The reversal of 21531103325 is 52330113512.

It can be written as a sum of positive squares in 6 ways, for example, as 54493924 + 21476609401 = 7382^2 + 146549^2 .

It is not a de Polignac number, because 21531103325 - 2⁶ = 21531103261 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21531103294 and 21531103303.

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, 427367 + ... + 475083.

It is an arithmetic number, because the mean of its divisors is an integer number (2225050575).

Almost surely, 2^21531103325 is an apocalyptic number.

21531103325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21531103325 is a deficient number, since it is larger than the sum of its proper divisors (5169503575).

21531103325 is a wasteful number, since it uses less digits than its factorization.

21531103325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65776 (or 65771 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 26.

Adding to 21531103325 its reverse (52330113512), we get a palindrome (73861216837).

The spelling of 21531103325 in words is "twenty-one billion, five hundred thirty-one million, one hundred three thousand, three hundred twenty-five".