405128138 has 16 divisors (see below), whose sum is σ = 612645000. Its totient is φ = 200918016.

The previous prime is 405128123. The next prime is 405128147. The reversal of 405128138 is 831821504.

It can be written as a sum of positive squares in 4 ways, for example, as 381147529 + 23980609 = 19523^2 + 4897^2 .

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 323738 + ... + 324986.

Almost surely, 2^405128138 is an apocalyptic number.

405128138 is a deficient number, since it is larger than the sum of its proper divisors (207516862).

405128138 is a wasteful number, since it uses less digits than its factorization.

405128138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2441.

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 405128138 is about 20127.7951599275. The cubic root of 405128138 is about 739.9416425857.

The spelling of 405128138 in words is "four hundred five million, one hundred twenty-eight thousand, one hundred thirty-eight".