21655561214363 has 2 divisors, whose sum is σ = 21655561214364. Its totient is φ = 21655561214362.

The previous prime is 21655561214327. The next prime is 21655561214377. The reversal of 21655561214363 is 36341216555612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21655561214363 - 2⁸ = 21655561214107 is a prime.

It is not a weakly prime, because it can be changed into another prime (21655561214303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10827780607181 + 10827780607182.

It is an arithmetic number, because the mean of its divisors is an integer number (10827780607182).

Almost surely, 2^{21655561214363} is an apocalyptic number.

21655561214363 is a deficient number, since it is larger than the sum of its proper divisors (1).

21655561214363 is an equidigital number, since it uses as much as digits as its factorization.

21655561214363 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888000, while the sum is 50.

Adding to 21655561214363 its reverse (36341216555612), we get a palindrome (57996777769975).

The spelling of 21655561214363 in words is "twenty-one trillion, six hundred fifty-five billion, five hundred sixty-one million, two hundred fourteen thousand, three hundred sixty-three".