228380821 has 2 divisors, whose sum is σ = 228380822. Its totient is φ = 228380820.

The previous prime is 228380819. The next prime is 228380827. The reversal of 228380821 is 128083822.

228380821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 169260100 + 59120721 = 13010^2 + 7689^2 .

It is a cyclic number.

It is not a de Polignac number, because 228380821 - 2¹ = 228380819 is a prime.

Together with 228380819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (228380827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 114190410 + 114190411.

It is an arithmetic number, because the mean of its divisors is an integer number (114190411).

Almost surely, 2^228380821 is an apocalyptic number.

It is an amenable number.

228380821 is a deficient number, since it is larger than the sum of its proper divisors (1).

228380821 is an equidigital number, since it uses as much as digits as its factorization.

228380821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12288, while the sum is 34.

The square root of 228380821 is about 15112.2738527331. The cubic root of 228380821 is about 611.2514137719.

The spelling of 228380821 in words is "two hundred twenty-eight million, three hundred eighty thousand, eight hundred twenty-one".