21330145225 has 12 divisors (see below), whose sum is σ = 28005226524. Its totient is φ = 16060344320.

The previous prime is 21330145159. The next prime is 21330145229. The reversal of 21330145225 is 52254103312.

It can be written as a sum of positive squares in 6 ways, for example, as 192765456 + 21137379769 = 13884^2 + 145387^2 .

It is not a de Polignac number, because 21330145225 - 2¹³ = 21330137033 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21330145193 and 21330145202.

It is not an unprimeable number, because it can be changed into a prime (21330145229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 25093864 + ... + 25094713.

It is an arithmetic number, because the mean of its divisors is an integer number (2333768877).

Almost surely, 2^21330145225 is an apocalyptic number.

21330145225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21330145225 is a deficient number, since it is larger than the sum of its proper divisors (6675081299).

21330145225 is a wasteful number, since it uses less digits than its factorization.

21330145225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50188604 (or 50188599 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 28.

Adding to 21330145225 its reverse (52254103312), we get a palindrome (73584248537).

The spelling of 21330145225 in words is "twenty-one billion, three hundred thirty million, one hundred forty-five thousand, two hundred twenty-five".