21531221414255 has 16 divisors (see below), whose sum is σ = 29552875673664. Its totient is φ = 14752094388480.

The previous prime is 21531221414239. The next prime is 21531221414257. The reversal of 21531221414255 is 55241412213512.

It is not a de Polignac number, because 21531221414255 - 2⁴ = 21531221414239 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21531221414257) 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, 253534526 + ... + 253619435.

It is an arithmetic number, because the mean of its divisors is an integer number (1847054729604).

Almost surely, 2^{21531221414255} is an apocalyptic number.

21531221414255 is a deficient number, since it is larger than the sum of its proper divisors (8021654259409).

21531221414255 is a wasteful number, since it uses less digits than its factorization.

21531221414255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 507155186.

The product of its digits is 96000, while the sum is 38.

Adding to 21531221414255 its reverse (55241412213512), we get a palindrome (76772633627767).

The spelling of 21531221414255 in words is "twenty-one trillion, five hundred thirty-one billion, two hundred twenty-one million, four hundred fourteen thousand, two hundred fifty-five".