40039665 has 32 divisors (see below), whose sum is σ = 68428800. Its totient is φ = 19943616.

The previous prime is 40039663. The next prime is 40039667. The reversal of 40039665 is 56693004.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (40039663) and next prime (40039667).

It is not a de Polignac number, because 40039665 - 2¹ = 40039663 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (40039663) 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, 13486 + ... + 16184.

It is an arithmetic number, because the mean of its divisors is an integer number (2138400).

Almost surely, 2^40039665 is an apocalyptic number.

It is an amenable number.

40039665 is a deficient number, since it is larger than the sum of its proper divisors (28389135).

40039665 is a wasteful number, since it uses less digits than its factorization.

40039665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2773.

The product of its (nonzero) digits is 19440, while the sum is 33.

The square root of 40039665 is about 6327.6903369239. The cubic root of 40039665 is about 342.1081956501.

It can be divided in two parts, 40039 and 665, that added together give a palindrome (40704).

The spelling of 40039665 in words is "forty million, thirty-nine thousand, six hundred sixty-five".