21025203244 has 48 divisors (see below), whose sum is σ = 37948629600. Its totient is φ = 10188412416.

The previous prime is 21025203223. The next prime is 21025203247. The reversal of 21025203244 is 44230252012.

It is not an unprimeable number, because it can be changed into a prime (21025203247) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5956072 + ... + 5959600.

It is an arithmetic number, because the mean of its divisors is an integer number (790596450).

Almost surely, 2^21025203244 is an apocalyptic number.

It is an amenable number.

21025203244 is a deficient number, since it is larger than the sum of its proper divisors (16923426356).

21025203244 is a wasteful number, since it uses less digits than its factorization.

21025203244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3922 (or 3920 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 25.

Adding to 21025203244 its reverse (44230252012), we get a palindrome (65255455256).

The spelling of 21025203244 in words is "twenty-one billion, twenty-five million, two hundred three thousand, two hundred forty-four".