21252210640144 has 45 divisors (see below), whose sum is σ = 45260176027269. Its totient is φ = 9660003545280.

The previous prime is 21252210640117. The next prime is 21252210640153. The reversal of 21252210640144 is 44104601225212.

The square root of 21252210640144 is 4610012.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 20377821072400 + 874389567744 = 4514180^2 + 935088^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 202788142 + ... + 202892914.

Almost surely, 2^{21252210640144} is an apocalyptic number.

21252210640144 is the 4610012-nd square number.

It is an amenable number.

21252210640144 is an abundant number, since it is smaller than the sum of its proper divisors (24007965387125).

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

21252210640144 is an frugal number, since it uses more digits than its factorization.

21252210640144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209576 (or 104786 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 34.

Adding to 21252210640144 its reverse (44104601225212), we get a palindrome (65356811865356).

The spelling of 21252210640144 in words is "twenty-one trillion, two hundred fifty-two billion, two hundred ten million, six hundred forty thousand, one hundred forty-four".