228761021 has 2 divisors, whose sum is σ = 228761022. Its totient is φ = 228761020.

The previous prime is 228761003. The next prime is 228761023. The reversal of 228761021 is 120167822.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 192820996 + 35940025 = 13886^2 + 5995^2 .

It is a cyclic number.

It is not a de Polignac number, because 228761021 - 2⁶ = 228760957 is a prime.

Together with 228761023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (228761023) 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, 114380510 + 114380511.

It is an arithmetic number, because the mean of its divisors is an integer number (114380511).

Almost surely, 2^228761021 is an apocalyptic number.

It is an amenable number.

228761021 is a deficient number, since it is larger than the sum of its proper divisors (1).

228761021 is an equidigital number, since it uses as much as digits as its factorization.

228761021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 228761021 is about 15124.8478008871. The cubic root of 228761021 is about 611.5904220173.

The spelling of 228761021 in words is "two hundred twenty-eight million, seven hundred sixty-one thousand, twenty-one".