21102320243 has 2 divisors, whose sum is σ = 21102320244. Its totient is φ = 21102320242.

The previous prime is 21102320191. The next prime is 21102320359. The reversal of 21102320243 is 34202320112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21102320243 - 2¹⁶ = 21102254707 is a prime.

It is not a weakly prime, because it can be changed into another prime (21102320443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551160121 + 10551160122.

It is an arithmetic number, because the mean of its divisors is an integer number (10551160122).

Almost surely, 2^21102320243 is an apocalyptic number.

21102320243 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102320243 is an equidigital number, since it uses as much as digits as its factorization.

21102320243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21102320243 its reverse (34202320112), we get a palindrome (55304640355).

The spelling of 21102320243 in words is "twenty-one billion, one hundred two million, three hundred twenty thousand, two hundred forty-three".