21221353453523 has 8 divisors (see below), whose sum is σ = 21236421294000. Its totient is φ = 21206290952448.

The previous prime is 21221353453499. The next prime is 21221353453541. The reversal of 21221353453523 is 32535435312212.

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

It is a cyclic number.

It is not a de Polignac number, because 21221353453523 - 2²⁴ = 21221336676307 is a prime.

It is a super-2 number, since 2×21221353453523² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21221353453583) 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, 6633803 + ... + 9297851.

It is an arithmetic number, because the mean of its divisors is an integer number (2654552661750).

Almost surely, 2^{21221353453523} is an apocalyptic number.

21221353453523 is a deficient number, since it is larger than the sum of its proper divisors (15067840477).

21221353453523 is a wasteful number, since it uses less digits than its factorization.

21221353453523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2669701.

The product of its digits is 648000, while the sum is 41.

Adding to 21221353453523 its reverse (32535435312212), we get a palindrome (53756788765735).

The spelling of 21221353453523 in words is "twenty-one trillion, two hundred twenty-one billion, three hundred fifty-three million, four hundred fifty-three thousand, five hundred twenty-three".