21655223410163 has 4 divisors (see below), whose sum is σ = 24748826754480. Its totient is φ = 18561620065848.

The previous prime is 21655223410153. The next prime is 21655223410169. The reversal of 21655223410163 is 36101432255612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21655223410163 - 2¹⁴ = 21655223393779 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21655223410163.

It is not an unprimeable number, because it can be changed into a prime (21655223410169) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1546801672148 + ... + 1546801672161.

It is an arithmetic number, because the mean of its divisors is an integer number (6187206688620).

Almost surely, 2^{21655223410163} is an apocalyptic number.

21655223410163 is a deficient number, since it is larger than the sum of its proper divisors (3093603344317).

21655223410163 is an equidigital number, since it uses as much as digits as its factorization.

21655223410163 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3093603344316.

The product of its (nonzero) digits is 259200, while the sum is 41.

Adding to 21655223410163 its reverse (36101432255612), we get a palindrome (57756655665775).

The spelling of 21655223410163 in words is "twenty-one trillion, six hundred fifty-five billion, two hundred twenty-three million, four hundred ten thousand, one hundred sixty-three".