40391985 has 8 divisors (see below), whose sum is σ = 64627200. Its totient is φ = 21542384.

The previous prime is 40391959. The next prime is 40391987. The reversal of 40391985 is 58919304.

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

It is a cyclic number.

It is not a de Polignac number, because 40391985 - 2¹⁶ = 40326449 is a prime.

It is not an unprimeable number, because it can be changed into a prime (40391987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1346385 + ... + 1346414.

It is an arithmetic number, because the mean of its divisors is an integer number (8078400).

Almost surely, 2^40391985 is an apocalyptic number.

It is an amenable number.

40391985 is a deficient number, since it is larger than the sum of its proper divisors (24235215).

40391985 is a wasteful number, since it uses less digits than its factorization.

40391985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2692807.

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 40391985 is about 6355.4689048095. The cubic root of 40391985 is about 343.1087014199.

The spelling of 40391985 in words is "forty million, three hundred ninety-one thousand, nine hundred eighty-five".