21655224340111 has 2 divisors, whose sum is σ = 21655224340112. Its totient is φ = 21655224340110.

The previous prime is 21655224340109. The next prime is 21655224340117. The reversal of 21655224340111 is 11104342255612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21655224340111 - 2¹ = 21655224340109 is a prime.

Together with 21655224340109, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21655224340117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10827612170055 + 10827612170056.

It is an arithmetic number, because the mean of its divisors is an integer number (10827612170056).

Almost surely, 2^{21655224340111} is an apocalyptic number.

21655224340111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21655224340111 is an equidigital number, since it uses as much as digits as its factorization.

21655224340111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 57600, while the sum is 37.

Adding to 21655224340111 its reverse (11104342255612), we get a palindrome (32759566595723).

The spelling of 21655224340111 in words is "twenty-one trillion, six hundred fifty-five billion, two hundred twenty-four million, three hundred forty thousand, one hundred eleven".