21113044420 has 48 divisors (see below), whose sum is σ = 47765415600. Its totient is φ = 7792736256.

The previous prime is 21113044391. The next prime is 21113044439. The reversal of 21113044420 is 2444031112.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 459330624 + 20653713796 = 21432^2 + 143714^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21113044391 and 21113044400.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 779424 + ... + 806056.

It is an arithmetic number, because the mean of its divisors is an integer number (995112825).

Almost surely, 2^21113044420 is an apocalyptic number.

21113044420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21113044420 is an abundant number, since it is smaller than the sum of its proper divisors (26652371180).

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

21113044420 is a wasteful number, since it uses less digits than its factorization.

21113044420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29704 (or 29702 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21113044420 its reverse (2444031112), we get a palindrome (23557075532).

The spelling of 21113044420 in words is "twenty-one billion, one hundred thirteen million, forty-four thousand, four hundred twenty".