228642821 has 8 divisors (see below), whose sum is σ = 249554304. Its totient is φ = 207752320.

The previous prime is 228642803. The next prime is 228642833. The reversal of 228642821 is 128246822.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-228642821 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 (228642881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25316 + ... + 33138.

It is an arithmetic number, because the mean of its divisors is an integer number (31194288).

Almost surely, 2^228642821 is an apocalyptic number.

It is an amenable number.

228642821 is a deficient number, since it is larger than the sum of its proper divisors (20911483).

228642821 is a wasteful number, since it uses less digits than its factorization.

228642821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10491.

The product of its digits is 24576, while the sum is 35.

The square root of 228642821 is about 15120.9398186753. The cubic root of 228642821 is about 611.4850683433.

The spelling of 228642821 in words is "two hundred twenty-eight million, six hundred forty-two thousand, eight hundred twenty-one".