228656021 has 16 divisors (see below), whose sum is σ = 253162368. Its totient is φ = 204792000.

The previous prime is 228656017. The next prime is 228656083. The reversal of 228656021 is 120656822.

It is a cyclic number.

It is not a de Polignac number, because 228656021 - 2² = 228656017 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 (228658021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 307376 + ... + 308118.

It is an arithmetic number, because the mean of its divisors is an integer number (15822648).

Almost surely, 2^228656021 is an apocalyptic number.

It is an amenable number.

228656021 is a deficient number, since it is larger than the sum of its proper divisors (24506347).

228656021 is a wasteful number, since it uses less digits than its factorization.

228656021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1132.

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 228656021 is about 15121.3762931818. The cubic root of 228656021 is about 611.4968355289.

The spelling of 228656021 in words is "two hundred twenty-eight million, six hundred fifty-six thousand, twenty-one".