21455521335450 has 120 divisors (see below), whose sum is σ = 59699613427740. Its totient is φ = 5713309728000.

The previous prime is 21455521335419. The next prime is 21455521335463. The reversal of 21455521335450 is 5453312555412.

21455521335450 is a `hidden beast` number, since 2 + 1 + 4 + 5 + 55 + 21 + 33 + 545 + 0 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 16138434149289 + 5317087186161 = 4017267^2 + 2305881^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21455521335396 and 21455521335405.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 939595 + ... + 6617694.

Almost surely, 2^{21455521335450} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21455521335450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29849806713870).

21455521335450 is an abundant number, since it is smaller than the sum of its proper divisors (38244092092290).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21455521335450 is a wasteful number, since it uses less digits than its factorization.

21455521335450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7558014 (or 7558000 counting only the distinct ones).

The product of its (nonzero) digits is 1800000, while the sum is 45.

The spelling of 21455521335450 in words is "twenty-one trillion, four hundred fifty-five billion, five hundred twenty-one million, three hundred thirty-five thousand, four hundred fifty".