402128 has 20 divisors (see below), whose sum is σ = 799428. Its totient is φ = 195840.

The previous prime is 402107. The next prime is 402131. The reversal of 402128 is 821204.

It can be written as a sum of positive squares in 2 ways, for example, as 7744 + 394384 = 88^2 + 628^2 .

It is a hoax number, since the sum of its digits (17) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

402128 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 (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 350 + ... + 962.

2⁴⁰²¹²⁸ is an apocalyptic number.

It is an amenable number.

402128 is a deficient number, since it is larger than the sum of its proper divisors (397300).

402128 is a wasteful number, since it uses less digits than its factorization.

402128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 662 (or 656 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 402128 is about 634.1356321797. The cubic root of 402128 is about 73.8110592681.

The spelling of 402128 in words is "four hundred two thousand, one hundred twenty-eight".