226821 has 12 divisors (see below), whose sum is σ = 352032. Its totient is φ = 129528.

The previous prime is 226819. The next prime is 226823. The reversal of 226821 is 128622.

226821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (226819) and next prime (226823).

It is not a de Polignac number, because 226821 - 2¹ = 226819 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (226823) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 625 + ... + 918.

It is an arithmetic number, because the mean of its divisors is an integer number (29336).

2²²⁶⁸²¹ is an apocalyptic number.

226821 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

226821 is a deficient number, since it is larger than the sum of its proper divisors (125211).

226821 is a wasteful number, since it uses less digits than its factorization.

226821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1560 (or 1553 counting only the distinct ones).

The product of its digits is 384, while the sum is 21.

The square root of 226821 is about 476.2572834089. The cubic root of 226821 is about 60.9856635663.

Multiplying 226821 by its sum of digits (21), we get a triangular number (4763241 = T₃₀₈₆).

226821 divided by its sum of digits (21) gives a palindrome (10801).

The spelling of 226821 in words is "two hundred twenty-six thousand, eight hundred twenty-one".