40128320 has 56 divisors (see below), whose sum is σ = 96697800. Its totient is φ = 15859712.

The previous prime is 40128311. The next prime is 40128349. The reversal of 40128320 is 2382104.

It can be written as a sum of positive squares in 4 ways, for example, as 1290496 + 38837824 = 1136^2 + 6232^2 .

It is a super-2 number, since 2×40128320² = 3220564132044800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 40128292 and 40128301.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27776 + ... + 29184.

Almost surely, 2^40128320 is an apocalyptic number.

40128320 is a gapful number since it is divisible by the number (40) 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 40128320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48348900).

40128320 is an abundant number, since it is smaller than the sum of its proper divisors (56569480).

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

40128320 is a wasteful number, since it uses less digits than its factorization.

40128320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1515 (or 1505 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 40128320 is about 6334.6917841360. The cubic root of 40128320 is about 342.3605058241.

The spelling of 40128320 in words is "forty million, one hundred twenty-eight thousand, three hundred twenty".