221345533 has 4 divisors (see below), whose sum is σ = 221396508. Its totient is φ = 221294560.

The previous prime is 221345519. The next prime is 221345539. The reversal of 221345533 is 335543122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 335543122 = 2 ⋅167771561.

It can be written as a sum of positive squares in 2 ways, for example, as 183927844 + 37417689 = 13562^2 + 6117^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221345533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221345539) 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, 18298 + ... + 27883.

It is an arithmetic number, because the mean of its divisors is an integer number (55349127).

Almost surely, 2^221345533 is an apocalyptic number.

It is an amenable number.

221345533 is a deficient number, since it is larger than the sum of its proper divisors (50975).

221345533 is an equidigital number, since it uses as much as digits as its factorization.

221345533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50974.

The product of its digits is 10800, while the sum is 28.

The square root of 221345533 is about 14877.6857407327. The cubic root of 221345533 is about 604.9092894986.

Adding to 221345533 its reverse (335543122), we get a palindrome (556888655).

The spelling of 221345533 in words is "two hundred twenty-one million, three hundred forty-five thousand, five hundred thirty-three".