228406640 has 120 divisors (see below), whose sum is σ = 674032752. Its totient is φ = 71178240.

The previous prime is 228406637. The next prime is 228406693. The reversal of 228406640 is 46604822.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 228406597 and 228406606.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 40472 + ... + 45768.

Almost surely, 2^228406640 is an apocalyptic number.

228406640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 228406640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (337016376).

228406640 is an abundant number, since it is smaller than the sum of its proper divisors (445626112).

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

228406640 is a wasteful number, since it uses less digits than its factorization.

228406640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5335 (or 5322 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 32.

The square root of 228406640 is about 15113.1280680076. The cubic root of 228406640 is about 611.2744473838.

The spelling of 228406640 in words is "two hundred twenty-eight million, four hundred six thousand, six hundred forty".