228022721 has 2 divisors, whose sum is σ = 228022722. Its totient is φ = 228022720.

The previous prime is 228022699. The next prime is 228022793. The reversal of 228022721 is 127220822.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 212022721 + 16000000 = 14561^2 + 4000^2 .

It is a cyclic number.

It is not a de Polignac number, because 228022721 - 2⁶ = 228022657 is a prime.

It is a super-2 number, since 2×228022721² = 103988722584487682, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (228022321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 114011360 + 114011361.

It is an arithmetic number, because the mean of its divisors is an integer number (114011361).

Almost surely, 2^228022721 is an apocalyptic number.

It is an amenable number.

228022721 is a deficient number, since it is larger than the sum of its proper divisors (1).

228022721 is an equidigital number, since it uses as much as digits as its factorization.

228022721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 228022721 is about 15100.4212192905. The cubic root of 228022721 is about 610.9317669122.

The spelling of 228022721 in words is "two hundred twenty-eight million, twenty-two thousand, seven hundred twenty-one".