400028 has 12 divisors (see below), whose sum is σ = 707952. Its totient is φ = 197760.

The previous prime is 400009. The next prime is 400031. The reversal of 400028 is 820004.

It is a junction number, because it is equal to n+sod(n) for n = 399985 and 400021.

It is a congruent number.

It is an unprimeable number.

400028 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128 + ... + 903.

It is an arithmetic number, because the mean of its divisors is an integer number (58996).

2⁴⁰⁰⁰²⁸ is an apocalyptic number.

It is an amenable number.

400028 is a deficient number, since it is larger than the sum of its proper divisors (307924).

400028 is a wasteful number, since it uses less digits than its factorization.

400028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1132 (or 1130 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 400028 is about 632.4776675899. The cubic root of 400028 is about 73.6823491474.

The spelling of 400028 in words is "four hundred thousand, twenty-eight".