21200524816 has 45 divisors (see below), whose sum is σ = 41644550631. Its totient is φ = 10455532032.

The previous prime is 21200524801. The next prime is 21200524837. The reversal of 21200524816 is 61842500212.

The square root of 21200524816 is 145604.

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

It can be written as a sum of positive squares in 4 ways, for example, as 510579216 + 20689945600 = 22596^2 + 143840^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 51834820 + ... + 51835228.

Almost surely, 2^21200524816 is an apocalyptic number.

21200524816 is the 145604-th square number.

It is an amenable number.

21200524816 is a deficient number, since it is larger than the sum of its proper divisors (20444025815).

21200524816 is an frugal number, since it uses more digits than its factorization.

21200524816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1004 (or 500 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 31.

The spelling of 21200524816 in words is "twenty-one billion, two hundred million, five hundred twenty-four thousand, eight hundred sixteen".