21510243205130 has 16 divisors (see below), whose sum is σ = 39001054105800. Its totient is φ = 8541293651712.

The previous prime is 21510243205117. The next prime is 21510243205141. The reversal of 21510243205130 is 3150234201512.

It can be written as a sum of positive squares in 4 ways, for example, as 19885686479569 + 1624556725561 = 4459337^2 + 1274581^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21510243205093 and 21510243205102.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 7850452355 + ... + 7850455094.

Almost surely, 2^{21510243205130} is an apocalyptic number.

21510243205130 is a deficient number, since it is larger than the sum of its proper divisors (17490810900670).

21510243205130 is a wasteful number, since it uses less digits than its factorization.

21510243205130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15700907593.

The product of its (nonzero) digits is 7200, while the sum is 29.

Adding to 21510243205130 its reverse (3150234201512), we get a palindrome (24660477406642).

The spelling of 21510243205130 in words is "twenty-one trillion, five hundred ten billion, two hundred forty-three million, two hundred five thousand, one hundred thirty".