21124063654256 has 20 divisors (see below), whose sum is σ = 40935697593504. Its totient is φ = 10560012662400.

The previous prime is 21124063654193. The next prime is 21124063654273. The reversal of 21124063654256 is 65245636042112.

It is a self number, because there is not a number n which added to its sum of digits gives 21124063654256.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126111485 + ... + 126278876.

Almost surely, 2^{21124063654256} is an apocalyptic number.

It is an amenable number.

21124063654256 is a deficient number, since it is larger than the sum of its proper divisors (19811633939248).

21124063654256 is a wasteful number, since it uses less digits than its factorization.

21124063654256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252395600 (or 252395594 counting only the distinct ones).

The product of its (nonzero) digits is 2073600, while the sum is 47.

Adding to 21124063654256 its reverse (65245636042112), we get a palindrome (86369699696368).

The spelling of 21124063654256 in words is "twenty-one trillion, one hundred twenty-four billion, sixty-three million, six hundred fifty-four thousand, two hundred fifty-six".