21802189111 has 4 divisors (see below), whose sum is σ = 22171717800. Its totient is φ = 21432660424.

The previous prime is 21802189063. The next prime is 21802189147. The reversal of 21802189111 is 11198120812.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21802189111 - 2⁹ = 21802188599 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21802181111) 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, 184764256 + ... + 184764373.

It is an arithmetic number, because the mean of its divisors is an integer number (5542929450).

Almost surely, 2^21802189111 is an apocalyptic number.

21802189111 is a deficient number, since it is larger than the sum of its proper divisors (369528689).

21802189111 is an equidigital number, since it uses as much as digits as its factorization.

21802189111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369528688.

The product of its (nonzero) digits is 2304, while the sum is 34.

The spelling of 21802189111 in words is "twenty-one billion, eight hundred two million, one hundred eighty-nine thousand, one hundred eleven".