40139665 has 4 divisors (see below), whose sum is σ = 48167604. Its totient is φ = 32111728.

The previous prime is 40139653. The next prime is 40139677. The reversal of 40139665 is 56693104.

40139665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (40139653) and next prime (40139677).

It can be written as a sum of positive squares in 2 ways, for example, as 12166144 + 27973521 = 3488^2 + 5289^2 .

It is a cyclic number.

It is not a de Polignac number, because 40139665 - 2¹⁷ = 40008593 is a prime.

It is a super-2 number, since 2×40139665² = 3222385412624450, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 40139665.

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 3 ways as a sum of consecutive naturals, for example, 4013962 + ... + 4013971.

It is an arithmetic number, because the mean of its divisors is an integer number (12041901).

Almost surely, 2^40139665 is an apocalyptic number.

It is an amenable number.

40139665 is a deficient number, since it is larger than the sum of its proper divisors (8027939).

40139665 is an equidigital number, since it uses as much as digits as its factorization.

40139665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8027938.

The product of its (nonzero) digits is 19440, while the sum is 34.

The square root of 40139665 is about 6335.5871866781. The cubic root of 40139665 is about 342.3927666145.

It can be divided in two parts, 40139 and 665, that added together give a palindrome (40804).

The spelling of 40139665 in words is "forty million, one hundred thirty-nine thousand, six hundred sixty-five".