21124130245 has 4 divisors (see below), whose sum is σ = 25348956300. Its totient is φ = 16899304192.

The previous prime is 21124130239. The next prime is 21124130299. The reversal of 21124130245 is 54203142112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8276814529 + 12847315716 = 90977^2 + 113346^2 .

It is a cyclic number.

It is not a de Polignac number, because 21124130245 - 2⁷ = 21124130117 is a prime.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 2112413020 + ... + 2112413029.

It is an arithmetic number, because the mean of its divisors is an integer number (6337239075).

Almost surely, 2^21124130245 is an apocalyptic number.

It is an amenable number.

21124130245 is a deficient number, since it is larger than the sum of its proper divisors (4224826055).

21124130245 is an equidigital number, since it uses as much as digits as its factorization.

21124130245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4224826054.

The product of its (nonzero) digits is 1920, while the sum is 25.

Adding to 21124130245 its reverse (54203142112), we get a palindrome (75327272357).

The spelling of 21124130245 in words is "twenty-one billion, one hundred twenty-four million, one hundred thirty thousand, two hundred forty-five".