21655561214327 has 2 divisors, whose sum is σ = 21655561214328. Its totient is φ = 21655561214326.

The previous prime is 21655561214303. The next prime is 21655561214363. The reversal of 21655561214327 is 72341216555612.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21655561214327 - 2⁴⁴ = 4063375169911 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21655561214377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10827780607163 + 10827780607164.

It is an arithmetic number, because the mean of its divisors is an integer number (10827780607164).

Almost surely, 2^{21655561214327} is an apocalyptic number.

21655561214327 is a deficient number, since it is larger than the sum of its proper divisors (1).

21655561214327 is an equidigital number, since it uses as much as digits as its factorization.

21655561214327 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024000, while the sum is 50.

Adding to 21655561214327 its reverse (72341216555612), we get a palindrome (93996777769939).

The spelling of 21655561214327 in words is "twenty-one trillion, six hundred fifty-five billion, five hundred sixty-one million, two hundred fourteen thousand, three hundred twenty-seven".