39891217 has 8 divisors (see below), whose sum is σ = 41053376. Its totient is φ = 38733552.

The previous prime is 39891209. The next prime is 39891227. The reversal of 39891217 is 71219893.

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 39891217 - 2³ = 39891209 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 39891217.

It is not an unprimeable number, because it can be changed into a prime (39891227) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26158 + ... + 27640.

It is an arithmetic number, because the mean of its divisors is an integer number (5131672).

Almost surely, 2^39891217 is an apocalyptic number.

39891217 is a gapful number since it is divisible by the number (37) formed by its first and last digit.

It is an amenable number.

39891217 is a deficient number, since it is larger than the sum of its proper divisors (1162159).

39891217 is a wasteful number, since it uses less digits than its factorization.

39891217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2247.

The product of its digits is 27216, while the sum is 40.

The square root of 39891217 is about 6315.9494139836. The cubic root of 39891217 is about 341.6848806735.

The spelling of 39891217 in words is "thirty-nine million, eight hundred ninety-one thousand, two hundred seventeen".