228128772 has 12 divisors (see below), whose sum is σ = 532300496. Its totient is φ = 76042920.

The previous prime is 228128759. The next prime is 228128773. The reversal of 228128772 is 277821822.

228128772 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×228128772² = 104085473228455968, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 228128772.

It is not an unprimeable number, because it can be changed into a prime (228128773) 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, 9505354 + ... + 9505377.

Almost surely, 2^228128772 is an apocalyptic number.

It is an amenable number.

228128772 is an abundant number, since it is smaller than the sum of its proper divisors (304171724).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

228128772 is a wasteful number, since it uses less digits than its factorization.

228128772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19010738 (or 19010736 counting only the distinct ones).

The product of its digits is 50176, while the sum is 39.

The square root of 228128772 is about 15103.9323356535. The cubic root of 228128772 is about 611.0264649066.

The spelling of 228128772 in words is "two hundred twenty-eight million, one hundred twenty-eight thousand, seven hundred seventy-two".