21559695513 has 8 divisors (see below), whose sum is σ = 28751424576. Its totient is φ = 14370548400.

The previous prime is 21559695503. The next prime is 21559695529. The reversal of 21559695513 is 31559695512.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21559695513 - 2¹³ = 21559687321 is a prime.

It is a super-2 number, since 2×21559695513² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21559695503) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 625918 + ... + 659463.

It is an arithmetic number, because the mean of its divisors is an integer number (3593928072).

Almost surely, 2^21559695513 is an apocalyptic number.

It is an amenable number.

21559695513 is a deficient number, since it is larger than the sum of its proper divisors (7191729063).

21559695513 is a wasteful number, since it uses less digits than its factorization.

21559695513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1290975.

The product of its digits is 1822500, while the sum is 51.

Subtracting 21559695513 from its reverse (31559695512), we obtain a palindrome (9999999999).

The spelling of 21559695513 in words is "twenty-one billion, five hundred fifty-nine million, six hundred ninety-five thousand, five hundred thirteen".