21118411843 has 8 divisors (see below), whose sum is σ = 21149661600. Its totient is φ = 21087187968.

The previous prime is 21118411841. The next prime is 21118411877. The reversal of 21118411843 is 34811481112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21118411843 - 2¹ = 21118411841 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21118411799 and 21118411808.

It is not an unprimeable number, because it can be changed into a prime (21118411841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2098618 + ... + 2108656.

It is an arithmetic number, because the mean of its divisors is an integer number (2643707700).

Almost surely, 2^21118411843 is an apocalyptic number.

21118411843 is a deficient number, since it is larger than the sum of its proper divisors (31249757).

21118411843 is a wasteful number, since it uses less digits than its factorization.

21118411843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12941.

The product of its digits is 6144, while the sum is 34.

Adding to 21118411843 its reverse (34811481112), we get a palindrome (55929892955).

The spelling of 21118411843 in words is "twenty-one billion, one hundred eighteen million, four hundred eleven thousand, eight hundred forty-three".