21221354461253 has 16 divisors (see below), whose sum is σ = 22495799520000. Its totient is φ = 19949818469376.

The previous prime is 21221354461249. The next prime is 21221354461271. The reversal of 21221354461253 is 35216445312212.

It is a cyclic number.

It is not a de Polignac number, because 21221354461253 - 2² = 21221354461249 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21221354461253.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221354461273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 124465700 + ... + 124636082.

It is an arithmetic number, because the mean of its divisors is an integer number (1405987470000).

Almost surely, 2^{21221354461253} is an apocalyptic number.

It is an amenable number.

21221354461253 is a deficient number, since it is larger than the sum of its proper divisors (1274445058747).

21221354461253 is a wasteful number, since it uses less digits than its factorization.

21221354461253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178876.

The product of its digits is 345600, while the sum is 41.

Adding to 21221354461253 its reverse (35216445312212), we get a palindrome (56437799773465).

The spelling of 21221354461253 in words is "twenty-one trillion, two hundred twenty-one billion, three hundred fifty-four million, four hundred sixty-one thousand, two hundred fifty-three".