228144781 has 2 divisors, whose sum is σ = 228144782. Its totient is φ = 228144780.

The previous prime is 228144767. The next prime is 228144803. The reversal of 228144781 is 187441822.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 204232681 + 23912100 = 14291^2 + 4890^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-228144781 is a prime.

It is a super-2 number, since 2×228144781² = 104100082195075922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 228144781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (228144281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 114072390 + 114072391.

It is an arithmetic number, because the mean of its divisors is an integer number (114072391).

Almost surely, 2^228144781 is an apocalyptic number.

It is an amenable number.

228144781 is a deficient number, since it is larger than the sum of its proper divisors (1).

228144781 is an equidigital number, since it uses as much as digits as its factorization.

228144781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28672, while the sum is 37.

The square root of 228144781 is about 15104.4622876817. The cubic root of 228144781 is about 611.0407575563.

The spelling of 228144781 in words is "two hundred twenty-eight million, one hundred forty-four thousand, seven hundred eighty-one".