40128 has 56 divisors (see below), whose sum is σ = 121920. Its totient is φ = 11520.

The previous prime is 40127. The next prime is 40129. The reversal of 40128 is 82104.

It is an interprime number because it is at equal distance from previous prime (40127) and next prime (40129).

It is a super-2 number, since 2×40128² = 3220512768, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (40123) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2103 + ... + 2121.

2⁴⁰¹²⁸ is an apocalyptic number.

40128 is a gapful number since it is divisible by the number (48) 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 40128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (60960).

40128 is an abundant number, since it is smaller than the sum of its proper divisors (81792).

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

40128 is a wasteful number, since it uses less digits than its factorization.

40128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45 (or 35 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 40128 is about 200.3197444088. The cubic root of 40128 is about 34.2359595780.

The spelling of 40128 in words is "forty thousand, one hundred twenty-eight".