21113205524240 has 20 divisors (see below), whose sum is σ = 49088202844044. Its totient is φ = 8445282209664.

The previous prime is 21113205524231. The next prime is 21113205524249. The reversal of 21113205524240 is 4242550231112.

It is an interprime number because it is at equal distance from previous prime (21113205524231) and next prime (21113205524249).

It can be written as a sum of positive squares in 2 ways, for example, as 16553050279936 + 4560155244304 = 4068544^2 + 2135452^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 21113205524197 and 21113205524206.

It is not an unprimeable number, because it can be changed into a prime (21113205524249) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131957534447 + ... + 131957534606.

Almost surely, 2^{21113205524240} is an apocalyptic number.

21113205524240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21113205524240 is an abundant number, since it is smaller than the sum of its proper divisors (27974997319804).

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

21113205524240 is a wasteful number, since it uses less digits than its factorization.

21113205524240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263915069066 (or 263915069060 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 32.

Adding to 21113205524240 its reverse (4242550231112), we get a palindrome (25355755755352).

The spelling of 21113205524240 in words is "twenty-one trillion, one hundred thirteen billion, two hundred five million, five hundred twenty-four thousand, two hundred forty".