21502550243344 has 20 divisors (see below), whose sum is σ = 41661328956796. Its totient is φ = 10751239544832.

The previous prime is 21502550243287. The next prime is 21502550243347. The reversal of 21502550243344 is 44334205520512.

It can be written as a sum of positive squares in 2 ways, for example, as 18035208316944 + 3467341926400 = 4246788^2 + 1862080^2 .

It is a super-2 number, since 2×21502550243344² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21502550243297 and 21502550243306.

It is not an unprimeable number, because it can be changed into a prime (21502550243347) 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 3 ways as a sum of consecutive naturals, for example, 3157312 + ... + 7278304.

Almost surely, 2^{21502550243344} is an apocalyptic number.

It is an amenable number.

21502550243344 is a deficient number, since it is larger than the sum of its proper divisors (20158778713452).

21502550243344 is a wasteful number, since it uses less digits than its factorization.

21502550243344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4447114 (or 4447108 counting only the distinct ones).

The product of its (nonzero) digits is 576000, while the sum is 40.

Adding to 21502550243344 its reverse (44334205520512), we get a palindrome (65836755763856).

The spelling of 21502550243344 in words is "twenty-one trillion, five hundred two billion, five hundred fifty million, two hundred forty-three thousand, three hundred forty-four".