21443542410521 has 8 divisors (see below), whose sum is σ = 26734806122304. Its totient is φ = 16709253826320.

The previous prime is 21443542410503. The next prime is 21443542410547. The reversal of 21443542410521 is 12501424534412.

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

It is not a de Polignac number, because 21443542410521 - 2¹⁸ = 21443542148377 is a prime.

It is a super-2 number, since 2×21443542410521² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21443542410551) 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, 139243781810 + ... + 139243781963.

It is an arithmetic number, because the mean of its divisors is an integer number (3341850765288).

Almost surely, 2^{21443542410521} is an apocalyptic number.

It is an amenable number.

21443542410521 is a deficient number, since it is larger than the sum of its proper divisors (5291263711783).

21443542410521 is a wasteful number, since it uses less digits than its factorization.

21443542410521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 278487563791.

The product of its (nonzero) digits is 153600, while the sum is 38.

Adding to 21443542410521 its reverse (12501424534412), we get a palindrome (33944966944933).

The spelling of 21443542410521 in words is "twenty-one trillion, four hundred forty-three billion, five hundred forty-two million, four hundred ten thousand, five hundred twenty-one".