228421 has 2 divisors, whose sum is σ = 228422. Its totient is φ = 228420.

The previous prime is 228419. The next prime is 228427. The reversal of 228421 is 124822.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 202500 + 25921 = 450^2 + 161^2 .

It is a cyclic number.

It is not a de Polignac number, because 228421 - 2¹ = 228419 is a prime.

Together with 228419, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (228427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 114210 + 114211.

It is an arithmetic number, because the mean of its divisors is an integer number (114211).

2²²⁸⁴²¹ is an apocalyptic number.

It is an amenable number.

228421 is a deficient number, since it is larger than the sum of its proper divisors (1).

228421 is an equidigital number, since it uses as much as digits as its factorization.

228421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 256, while the sum is 19.

The square root of 228421 is about 477.9340958752. The cubic root of 228421 is about 61.1287257457.

The spelling of 228421 in words is "two hundred twenty-eight thousand, four hundred twenty-one".