21455005121543 has 8 divisors (see below), whose sum is σ = 24529090723200. Its totient is φ = 18383190737400.

The previous prime is 21455005121521. The next prime is 21455005121551. The reversal of 21455005121543 is 34512150055412.

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 21455005121543 - 2¹⁶ = 21455005056007 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21455005121497 and 21455005121506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21455005121503) 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 7 ways as a sum of consecutive naturals, for example, 567784133 + ... + 567821918.

It is an arithmetic number, because the mean of its divisors is an integer number (3066136340400).

Almost surely, 2^{21455005121543} is an apocalyptic number.

21455005121543 is a deficient number, since it is larger than the sum of its proper divisors (3074085601657).

21455005121543 is a wasteful number, since it uses less digits than its factorization.

21455005121543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1135608757.

The product of its (nonzero) digits is 120000, while the sum is 38.

Adding to 21455005121543 its reverse (34512150055412), we get a palindrome (55967155176955).

The spelling of 21455005121543 in words is "twenty-one trillion, four hundred fifty-five billion, five million, one hundred twenty-one thousand, five hundred forty-three".