21455040200144 has 20 divisors (see below), whose sum is σ = 42353463792996. Its totient is φ = 10525114060032.

The previous prime is 21455040200141. The next prime is 21455040200249. The reversal of 21455040200144 is 44100204055412.

It can be written as a sum of positive squares in 2 ways, for example, as 6554050567744 + 14900989632400 = 2560088^2 + 3860180^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21455040200144.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21455040200141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12650376629 + ... + 12650378324.

Almost surely, 2^{21455040200144} is an apocalyptic number.

It is an amenable number.

21455040200144 is a deficient number, since it is larger than the sum of its proper divisors (20898423592852).

21455040200144 is a wasteful number, since it uses less digits than its factorization.

21455040200144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25300755014 (or 25300755008 counting only the distinct ones).

The product of its (nonzero) digits is 25600, while the sum is 32.

Adding to 21455040200144 its reverse (44100204055412), we get a palindrome (65555244255556).

The spelling of 21455040200144 in words is "twenty-one trillion, four hundred fifty-five billion, forty million, two hundred thousand, one hundred forty-four".