221155111553 has 8 divisors (see below), whose sum is σ = 236236487688. Its totient is φ = 206303985664.

The previous prime is 221155111543. The next prime is 221155111579. The reversal of 221155111553 is 355111551122.

It can be written as a sum of positive squares in 4 ways, for example, as 9433654129 + 211721457424 = 97127^2 + 460132^2 .

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 221155111553 - 2²⁰ = 221154062977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221155111543) 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, 57560576 + ... + 57564417.

It is an arithmetic number, because the mean of its divisors is an integer number (29529560961).

Almost surely, 2^221155111553 is an apocalyptic number.

It is an amenable number.

221155111553 is a deficient number, since it is larger than the sum of its proper divisors (15081376135).

221155111553 is a wasteful number, since it uses less digits than its factorization.

221155111553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115125123.

The product of its digits is 7500, while the sum is 32.

Adding to 221155111553 its reverse (355111551122), we get a palindrome (576266662675).

The spelling of 221155111553 in words is "two hundred twenty-one billion, one hundred fifty-five million, one hundred eleven thousand, five hundred fifty-three".