21531514042221 has 8 divisors (see below), whose sum is σ = 28823062623264. Its totient is φ = 14297154078000.

The previous prime is 21531514042183. The next prime is 21531514042301. The reversal of 21531514042221 is 12224041513512.

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

It is not a de Polignac number, because 21531514042221 - 2¹¹ = 21531514040173 is a prime.

It is a super-2 number, since 2×21531514042221² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21531514040221) 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, 14297153326 + ... + 14297154831.

It is an arithmetic number, because the mean of its divisors is an integer number (3602882827908).

Almost surely, 2^{21531514042221} is an apocalyptic number.

It is an amenable number.

21531514042221 is a deficient number, since it is larger than the sum of its proper divisors (7291548581043).

21531514042221 is a wasteful number, since it uses less digits than its factorization.

21531514042221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28594308411.

The product of its (nonzero) digits is 19200, while the sum is 33.

Adding to 21531514042221 its reverse (12224041513512), we get a palindrome (33755555555733).

The spelling of 21531514042221 in words is "twenty-one trillion, five hundred thirty-one billion, five hundred fourteen million, forty-two thousand, two hundred twenty-one".