21125554325245 has 8 divisors (see below), whose sum is σ = 25350754313016. Its totient is φ = 16900384045056.

The previous prime is 21125554325243. The next prime is 21125554325257. The reversal of 21125554325245 is 54252345552112.

It can be written as a sum of positive squares in 4 ways, for example, as 124543350649 + 21001010974596 = 352907^2 + 4582686^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21125554325245 - 2¹ = 21125554325243 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21125554325195 and 21125554325204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21125554325243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5831272 + ... + 8732401.

It is an arithmetic number, because the mean of its divisors is an integer number (3168844289127).

Almost surely, 2^{21125554325245} is an apocalyptic number.

It is an amenable number.

21125554325245 is a deficient number, since it is larger than the sum of its proper divisors (4225199987771).

21125554325245 is a wasteful number, since it uses less digits than its factorization.

21125554325245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14853791.

The product of its digits is 2400000, while the sum is 46.

Adding to 21125554325245 its reverse (54252345552112), we get a palindrome (75377899877357).

The spelling of 21125554325245 in words is "twenty-one trillion, one hundred twenty-five billion, five hundred fifty-four million, three hundred twenty-five thousand, two hundred forty-five".