228721387 has 2 divisors, whose sum is σ = 228721388. Its totient is φ = 228721386.

The previous prime is 228721333. The next prime is 228721399. The reversal of 228721387 is 783127822.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 228721387 - 2¹¹ = 228719339 is a prime.

It is not a weakly prime, because it can be changed into another prime (228721187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 114360693 + 114360694.

It is an arithmetic number, because the mean of its divisors is an integer number (114360694).

Almost surely, 2^228721387 is an apocalyptic number.

228721387 is a deficient number, since it is larger than the sum of its proper divisors (1).

228721387 is an equidigital number, since it uses as much as digits as its factorization.

228721387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 75264, while the sum is 40.

The square root of 228721387 is about 15123.5375160708. The cubic root of 228721387 is about 611.5550996028. Note that the first 3 decimals are identical.

The spelling of 228721387 in words is "two hundred twenty-eight million, seven hundred twenty-one thousand, three hundred eighty-seven".