40388917 has 4 divisors (see below), whose sum is σ = 40598380. Its totient is φ = 40179456.

The previous prime is 40388899. The next prime is 40388947. The reversal of 40388917 is 71988304.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7107556 + 33281361 = 2666^2 + 5769^2 .

It is a cyclic number.

It is not a de Polignac number, because 40388917 - 2¹⁵ = 40356149 is a prime.

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 40388917.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40388947) 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 3 ways as a sum of consecutive naturals, for example, 104442 + ... + 104827.

It is an arithmetic number, because the mean of its divisors is an integer number (10149595).

Almost surely, 2^40388917 is an apocalyptic number.

It is an amenable number.

40388917 is a deficient number, since it is larger than the sum of its proper divisors (209463).

40388917 is a wasteful number, since it uses less digits than its factorization.

40388917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209462.

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 40388917 is about 6355.2275332989. The cubic root of 40388917 is about 343.1000141837.

The spelling of 40388917 in words is "forty million, three hundred eighty-eight thousand, nine hundred seventeen".