21113240556 has 24 divisors (see below), whose sum is σ = 50853397504. Its totient is φ = 6810722640.

The previous prime is 21113240543. The next prime is 21113240573. The reversal of 21113240556 is 65504231112.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28377640 + ... + 28378383.

Almost surely, 2^21113240556 is an apocalyptic number.

It is an amenable number.

21113240556 is an abundant number, since it is smaller than the sum of its proper divisors (29740156948).

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

21113240556 is a wasteful number, since it uses less digits than its factorization.

21113240556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56756061 (or 56756059 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

Adding to 21113240556 its reverse (65504231112), we get a palindrome (86617471668).

The spelling of 21113240556 in words is "twenty-one billion, one hundred thirteen million, two hundred forty thousand, five hundred fifty-six".