21240124043 has 2 divisors, whose sum is σ = 21240124044. Its totient is φ = 21240124042.

The previous prime is 21240124033. The next prime is 21240124057. The reversal of 21240124043 is 34042104212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21240124043 - 2⁴ = 21240124027 is a prime.

It is a super-2 number, since 2×21240124043² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21240124013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10620062021 + 10620062022.

It is an arithmetic number, because the mean of its divisors is an integer number (10620062022).

Almost surely, 2^21240124043 is an apocalyptic number.

21240124043 is a deficient number, since it is larger than the sum of its proper divisors (1).

21240124043 is an equidigital number, since it uses as much as digits as its factorization.

21240124043 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21240124043 its reverse (34042104212), we get a palindrome (55282228255).

The spelling of 21240124043 in words is "twenty-one billion, two hundred forty million, one hundred twenty-four thousand, forty-three".