21121030225 has 6 divisors (see below), whose sum is σ = 26190077510. Its totient is φ = 16896824160.

The previous prime is 21121030201. The next prime is 21121030237. The reversal of 21121030225 is 52203012112.

It can be written as a sum of positive squares in 3 ways, for example, as 5374795969 + 15746234256 = 73313^2 + 125484^2 .

It is not a de Polignac number, because 21121030225 - 2⁵ = 21121030193 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 422420580 + ... + 422420629.

Almost surely, 2^21121030225 is an apocalyptic number.

21121030225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21121030225 is a deficient number, since it is larger than the sum of its proper divisors (5069047285).

21121030225 is an equidigital number, since it uses as much as digits as its factorization.

21121030225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 844841219 (or 844841214 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

Adding to 21121030225 its reverse (52203012112), we get a palindrome (73324042337).

The spelling of 21121030225 in words is "twenty-one billion, one hundred twenty-one million, thirty thousand, two hundred twenty-five".