228520133 has 4 divisors (see below), whose sum is σ = 229041120. Its totient is φ = 227999148.

The previous prime is 228520129. The next prime is 228520139. The reversal of 228520133 is 331025822.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 331025822 = 2 ⋅165512911.

It is a cyclic number.

It is not a de Polignac number, because 228520133 - 2² = 228520129 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 (228520139) 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, 259835 + ... + 260712.

It is an arithmetic number, because the mean of its divisors is an integer number (57260280).

Almost surely, 2^228520133 is an apocalyptic number.

It is an amenable number.

228520133 is a deficient number, since it is larger than the sum of its proper divisors (520987).

228520133 is an equidigital number, since it uses as much as digits as its factorization.

228520133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520986.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 228520133 is about 15116.8823836134. The cubic root of 228520133 is about 611.3756760278.

Adding to 228520133 its reverse (331025822), we get a palindrome (559545955).

The spelling of 228520133 in words is "two hundred twenty-eight million, five hundred twenty thousand, one hundred thirty-three".