21255130513 has 8 divisors (see below), whose sum is σ = 21314241000. Its totient is φ = 21196051200.

The previous prime is 21255130511. The next prime is 21255130517. The reversal of 21255130513 is 31503155212.

It can be written as a sum of positive squares in 4 ways, for example, as 6183148689 + 15071981824 = 78633^2 + 122768^2 .

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 21255130513 - 2¹ = 21255130511 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21255130511) 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 7 ways as a sum of consecutive naturals, for example, 2175363 + ... + 2185111.

It is an arithmetic number, because the mean of its divisors is an integer number (2664280125).

Almost surely, 2^21255130513 is an apocalyptic number.

It is an amenable number.

21255130513 is a deficient number, since it is larger than the sum of its proper divisors (59110487).

21255130513 is an equidigital number, since it uses as much as digits as its factorization.

21255130513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15587.

The product of its (nonzero) digits is 4500, while the sum is 28.

Adding to 21255130513 its reverse (31503155212), we get a palindrome (52758285725).

The spelling of 21255130513 in words is "twenty-one billion, two hundred fifty-five million, one hundred thirty thousand, five hundred thirteen".