17997 has 8 divisors (see below), whose sum is σ = 27456. Its totient is φ = 10272.

The previous prime is 17989. The next prime is 18013. The reversal of 17997 is 79971.

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

It is not a de Polignac number, because 17997 - 2³ = 17989 is a prime.

It is an Ulam number.

17997 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 408 + ... + 449.

It is an arithmetic number, because the mean of its divisors is an integer number (3432).

2¹⁷⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

17997 is a deficient number, since it is larger than the sum of its proper divisors (9459).

17997 is an equidigital number, since it uses as much as digits as its factorization.

17997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 867.

The product of its digits is 3969, while the sum is 33.

The square root of 17997 is about 134.1528978442. The cubic root of 17997 is about 26.2059578938.

Subtracting from 17997 its product of digits (3969), we obtain a triangular number (14028 = T₁₆₇).

It can be divided in two parts, 179 and 97, that added together give a triangular number (276 = T₂₃).

The spelling of 17997 in words is "seventeen thousand, nine hundred ninety-seven".