21253225264636 has 12 divisors (see below), whose sum is σ = 37194329720520. Its totient is φ = 10626273915920.

The previous prime is 21253225264589. The next prime is 21253225264639. The reversal of 21253225264636 is 63646252235212.

It is a self number, because there is not a number n which added to its sum of digits gives 21253225264636.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21253225264639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84537895 + ... + 84788926.

It is an arithmetic number, because the mean of its divisors is an integer number (3099527476710).

Almost surely, 2^{21253225264636} is an apocalyptic number.

It is an amenable number.

21253225264636 is a deficient number, since it is larger than the sum of its proper divisors (15941104455884).

21253225264636 is a wasteful number, since it uses less digits than its factorization.

21253225264636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169358204 (or 169358202 counting only the distinct ones).

The product of its digits is 6220800, while the sum is 49.

Adding to 21253225264636 its reverse (63646252235212), we get a palindrome (84899477499848).

The spelling of 21253225264636 in words is "twenty-one trillion, two hundred fifty-three billion, two hundred twenty-five million, two hundred sixty-four thousand, six hundred thirty-six".