228143821 has 4 divisors (see below), whose sum is σ = 229011552. Its totient is φ = 227276092.

The previous prime is 228143819. The next prime is 228143827. The reversal of 228143821 is 128341822.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 228143821 - 2¹ = 228143819 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228143827) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 433471 + ... + 433996.

It is an arithmetic number, because the mean of its divisors is an integer number (57252888).

Almost surely, 2^228143821 is an apocalyptic number.

It is an amenable number.

228143821 is a deficient number, since it is larger than the sum of its proper divisors (867731).

228143821 is an equidigital number, since it uses as much as digits as its factorization.

228143821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 867730.

The product of its digits is 6144, while the sum is 31.

The square root of 228143821 is about 15104.4305089599. The cubic root of 228143821 is about 611.0399004982.

The spelling of 228143821 in words is "two hundred twenty-eight million, one hundred forty-three thousand, eight hundred twenty-one".