21124235243 has 2 divisors, whose sum is σ = 21124235244. Its totient is φ = 21124235242.

The previous prime is 21124235227. The next prime is 21124235261. The reversal of 21124235243 is 34253242112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21124235243 - 2⁴ = 21124235227 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21124265243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10562117621 + 10562117622.

It is an arithmetic number, because the mean of its divisors is an integer number (10562117622).

Almost surely, 2^21124235243 is an apocalyptic number.

21124235243 is a deficient number, since it is larger than the sum of its proper divisors (1).

21124235243 is an equidigital number, since it uses as much as digits as its factorization.

21124235243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 29.

Adding to 21124235243 its reverse (34253242112), we get a palindrome (55377477355).

The spelling of 21124235243 in words is "twenty-one billion, one hundred twenty-four million, two hundred thirty-five thousand, two hundred forty-three".