40209865 has 16 divisors (see below), whose sum is σ = 50554368. Its totient is φ = 30644416.

The previous prime is 40209853. The next prime is 40209887. The reversal of 40209865 is 56890204.

It is a happy number.

40209865 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 40209865 - 2¹⁷ = 40078793 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 40209865.

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 15 ways as a sum of consecutive naturals, for example, 35904 + ... + 37006.

It is an arithmetic number, because the mean of its divisors is an integer number (3159648).

Almost surely, 2^40209865 is an apocalyptic number.

It is an amenable number.

40209865 is a deficient number, since it is larger than the sum of its proper divisors (10344503).

40209865 is a wasteful number, since it uses less digits than its factorization.

40209865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1448.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 40209865 is about 6341.1249002050. The cubic root of 40209865 is about 342.5922531963.

The spelling of 40209865 in words is "forty million, two hundred nine thousand, eight hundred sixty-five".