13621355563 has 4 divisors (see below), whose sum is σ = 13622001120. Its totient is φ = 13620710008.

The previous prime is 13621355557. The next prime is 13621355567. The reversal of 13621355563 is 36555312631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 36555312631 = 41 ⋅891592991.

It is a cyclic number.

It is not a de Polignac number, because 13621355563 - 2²⁵ = 13587801131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13621355567) 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, 290020 + ... + 333697.

It is an arithmetic number, because the mean of its divisors is an integer number (3405500280).

Almost surely, 2^13621355563 is an apocalyptic number.

13621355563 is a deficient number, since it is larger than the sum of its proper divisors (645557).

13621355563 is an equidigital number, since it uses as much as digits as its factorization.

13621355563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645556.

The product of its digits is 243000, while the sum is 40.

The spelling of 13621355563 in words is "thirteen billion, six hundred twenty-one million, three hundred fifty-five thousand, five hundred sixty-three".