20170128 has 40 divisors (see below), whose sum is σ = 56844576. Its totient is φ = 6112000.

The previous prime is 20170121. The next prime is 20170141. The reversal of 20170128 is 82107102.

It is a hoax number, since the sum of its digits (21) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (20170121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18573 + ... + 19628.

Almost surely, 2^20170128 is an apocalyptic number.

It is an amenable number.

20170128 is an abundant number, since it is smaller than the sum of its proper divisors (36674448).

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

20170128 is a wasteful number, since it uses less digits than its factorization.

20170128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38223 (or 38217 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 20170128 is about 4491.1165649535. The cubic root of 20170128 is about 272.2092536250.

The spelling of 20170128 in words is "twenty million, one hundred seventy thousand, one hundred twenty-eight".