21885236843 has 2 divisors, whose sum is σ = 21885236844. Its totient is φ = 21885236842.

The previous prime is 21885236809. The next prime is 21885236917. The reversal of 21885236843 is 34863258812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21885236843 - 2²⁸ = 21616801387 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 21885236791 and 21885236800.

It is not a weakly prime, because it can be changed into another prime (21885236743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10942618421 + 10942618422.

It is an arithmetic number, because the mean of its divisors is an integer number (10942618422).

Almost surely, 2^21885236843 is an apocalyptic number.

21885236843 is a deficient number, since it is larger than the sum of its proper divisors (1).

21885236843 is an equidigital number, since it uses as much as digits as its factorization.

21885236843 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2211840, while the sum is 50.

The spelling of 21885236843 in words is "twenty-one billion, eight hundred eighty-five million, two hundred thirty-six thousand, eight hundred forty-three".