21256234523635 has 16 divisors (see below), whose sum is σ = 25541800673472. Its totient is φ = 16982109529600.

The previous prime is 21256234523621. The next prime is 21256234523669. The reversal of 21256234523635 is 53632543265212.

It is not a de Polignac number, because 21256234523635 - 2¹³ = 21256234515443 is a prime.

It is a super-2 number, since 2×21256234523635² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 159465615 + ... + 159598855.

It is an arithmetic number, because the mean of its divisors is an integer number (1596362542092).

Almost surely, 2^{21256234523635} is an apocalyptic number.

21256234523635 is a deficient number, since it is larger than the sum of its proper divisors (4285566149837).

21256234523635 is a wasteful number, since it uses less digits than its factorization.

21256234523635 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175934.

The product of its digits is 7776000, while the sum is 49.

Adding to 21256234523635 its reverse (53632543265212), we get a palindrome (74888777788847).

The spelling of 21256234523635 in words is "twenty-one trillion, two hundred fifty-six billion, two hundred thirty-four million, five hundred twenty-three thousand, six hundred thirty-five".