21013255210 has 16 divisors (see below), whose sum is σ = 38019841416. Its totient is φ = 8361750528.

The previous prime is 21013255187. The next prime is 21013255217. The reversal of 21013255210 is 1255231012.

It can be written as a sum of positive squares in 4 ways, for example, as 19133252329 + 1880002881 = 138323^2 + 43359^2 .

It is not an unprimeable number, because it can be changed into a prime (21013255217) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 5441919 + ... + 5445778.

Almost surely, 2^21013255210 is an apocalyptic number.

21013255210 is a deficient number, since it is larger than the sum of its proper divisors (17006586206).

21013255210 is a wasteful number, since it uses less digits than its factorization.

21013255210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10887897.

The product of its (nonzero) digits is 600, while the sum is 22.

Adding to 21013255210 its reverse (1255231012), we get a palindrome (22268486222).

The spelling of 21013255210 in words is "twenty-one billion, thirteen million, two hundred fifty-five thousand, two hundred ten".