40128738 has 64 divisors (see below), whose sum is σ = 93405312. Its totient is φ = 11381760.

The previous prime is 40128733. The next prime is 40128769. The reversal of 40128738 is 83782104.

It is a super-2 number, since 2×40128738² = 3220631226945288, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 40128699 and 40128708.

It is not an unprimeable number, because it can be changed into a prime (40128731) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 69993 + ... + 70563.

It is an arithmetic number, because the mean of its divisors is an integer number (1459458).

Almost surely, 2^40128738 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 40128738, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46702656).

40128738 is an abundant number, since it is smaller than the sum of its proper divisors (53276574).

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

40128738 is a wasteful number, since it uses less digits than its factorization.

40128738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 659.

The product of its (nonzero) digits is 10752, while the sum is 33.

The square root of 40128738 is about 6334.7247769733. The cubic root of 40128738 is about 342.3616945622.

It can be divided in two parts, 40 and 128738, that added together give a triangular number (128778 = T₅₀₇).

The spelling of 40128738 in words is "forty million, one hundred twenty-eight thousand, seven hundred thirty-eight".