40128639 has 8 divisors (see below), whose sum is σ = 53567232. Its totient is φ = 26721240.

The previous prime is 40128631. The next prime is 40128643. The reversal of 40128639 is 93682104.

40128639 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 40128639 - 2³ = 40128631 is a prime.

It is a super-2 number, since 2×40128639² = 3220615335984642, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40128631) by changing a digit.

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, 4609 + ... + 10074.

It is an arithmetic number, because the mean of its divisors is an integer number (6695904).

Almost surely, 2^40128639 is an apocalyptic number.

40128639 is a deficient number, since it is larger than the sum of its proper divisors (13438593).

40128639 is a wasteful number, since it uses less digits than its factorization.

40128639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15597.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 40128639 is about 6334.7169628958. The cubic root of 40128639 is about 342.3614130197.

The spelling of 40128639 in words is "forty million, one hundred twenty-eight thousand, six hundred thirty-nine".