228313721 has 2 divisors, whose sum is σ = 228313722. Its totient is φ = 228313720.

The previous prime is 228313697. The next prime is 228313739. The reversal of 228313721 is 127313822.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 222606400 + 5707321 = 14920^2 + 2389^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-228313721 is a prime.

It is not a weakly prime, because it can be changed into another prime (228313021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 114156860 + 114156861.

It is an arithmetic number, because the mean of its divisors is an integer number (114156861).

Almost surely, 2^228313721 is an apocalyptic number.

It is an amenable number.

228313721 is a deficient number, since it is larger than the sum of its proper divisors (1).

228313721 is an equidigital number, since it uses as much as digits as its factorization.

228313721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4032, while the sum is 29.

The square root of 228313721 is about 15110.0536398783. The cubic root of 228313721 is about 611.1915444899.

The spelling of 228313721 in words is "two hundred twenty-eight million, three hundred thirteen thousand, seven hundred twenty-one".