221556635455 has 8 divisors (see below), whose sum is σ = 265887081792. Its totient is φ = 177232562208.

The previous prime is 221556635441. The next prime is 221556635459. The reversal of 221556635455 is 554536655122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221556635455 - 2¹³ = 221556627263 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221556635399 and 221556635408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221556635459) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1516452 + ... + 1656121.

It is an arithmetic number, because the mean of its divisors is an integer number (33235885224).

Almost surely, 2^221556635455 is an apocalyptic number.

221556635455 is a deficient number, since it is larger than the sum of its proper divisors (44330446337).

221556635455 is a wasteful number, since it uses less digits than its factorization.

221556635455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3186545.

The product of its digits is 5400000, while the sum is 49.

The spelling of 221556635455 in words is "two hundred twenty-one billion, five hundred fifty-six million, six hundred thirty-five thousand, four hundred fifty-five".