393128 has 16 divisors (see below), whose sum is σ = 744180. Its totient is φ = 194688.

The previous prime is 393121. The next prime is 393137. The reversal of 393128 is 821393.

It is a Cunningham number, because it is equal to 627²-1.

It can be written as a sum of positive squares in 2 ways, for example, as 315844 + 77284 = 562^2 + 278^2 .

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 393097 and 393106.

It is not an unprimeable number, because it can be changed into a prime (393121) by changing a digit.

393128 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1100 + ... + 1412.

2³⁹³¹²⁸ is an apocalyptic number.

It is an amenable number.

393128 is a deficient number, since it is larger than the sum of its proper divisors (351052).

393128 is a wasteful number, since it uses less digits than its factorization.

393128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476 (or 472 counting only the distinct ones).

The product of its digits is 1296, while the sum is 26.

The square root of 393128 is about 626.9992025513. Note that the first 3 decimals coincide. The cubic root of 393128 is about 73.2562459001.

The spelling of 393128 in words is "three hundred ninety-three thousand, one hundred twenty-eight".