21500450444455 has 64 divisors (see below), whose sum is σ = 26229535488000. Its totient is φ = 16917953310720.

The previous prime is 21500450444387. The next prime is 21500450444471. The reversal of 21500450444455 is 55444405400512.

It is not a de Polignac number, because 21500450444455 - 2³³ = 21491860509863 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 28937348814 + ... + 28937349556.

It is an arithmetic number, because the mean of its divisors is an integer number (409836492000).

Almost surely, 2^{21500450444455} is an apocalyptic number.

21500450444455 is a deficient number, since it is larger than the sum of its proper divisors (4729085043545).

21500450444455 is a wasteful number, since it uses less digits than its factorization.

21500450444455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1904.

The product of its (nonzero) digits is 1280000, while the sum is 43.

Adding to 21500450444455 its reverse (55444405400512), we get a palindrome (76944855844967).

The spelling of 21500450444455 in words is "twenty-one trillion, five hundred billion, four hundred fifty million, four hundred forty-four thousand, four hundred fifty-five".