21224406355444 has 12 divisors (see below), whose sum is σ = 37142928989824. Its totient is φ = 10612140929784.

The previous prime is 21224406355423. The next prime is 21224406355457. The reversal of 21224406355444 is 44455360442212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21224406355394 and 21224406355403.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14790564 + ... + 16161979.

Almost surely, 2^{21224406355444} is an apocalyptic number.

It is an amenable number.

21224406355444 is a deficient number, since it is larger than the sum of its proper divisors (15918522634380).

21224406355444 is a wasteful number, since it uses less digits than its factorization.

21224406355444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31123974 (or 31123972 counting only the distinct ones).

The product of its (nonzero) digits is 3686400, while the sum is 46.

Adding to 21224406355444 its reverse (44455360442212), we get a palindrome (65679766797656).

The spelling of 21224406355444 in words is "twenty-one trillion, two hundred twenty-four billion, four hundred six million, three hundred fifty-five thousand, four hundred forty-four".