21744312011 has 2 divisors, whose sum is σ = 21744312012. Its totient is φ = 21744312010.

The previous prime is 21744311957. The next prime is 21744312049. The reversal of 21744312011 is 11021344712.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21744312011 is a prime.

It is not a weakly prime, because it can be changed into another prime (21744312311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10872156005 + 10872156006.

It is an arithmetic number, because the mean of its divisors is an integer number (10872156006).

Almost surely, 2^21744312011 is an apocalyptic number.

21744312011 is a deficient number, since it is larger than the sum of its proper divisors (1).

21744312011 is an equidigital number, since it uses as much as digits as its factorization.

21744312011 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 26.

Adding to 21744312011 its reverse (11021344712), we get a palindrome (32765656723).

The spelling of 21744312011 in words is "twenty-one billion, seven hundred forty-four million, three hundred twelve thousand, eleven".