Search a number
BaseRepresentation
bin100001001011101
3212022020
410021131
51020424
6210353
7100350
oct41135
925266
1016989
1111845
1299b9
13796b
146297
155079
hex425d

16989 has 8 divisors (see below), whose sum is σ = 25920. Its totient is φ = 9696.

The previous prime is 16987. The next prime is 16993. The reversal of 16989 is 98961.

It is a happy number.

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

It is not a de Polignac number, because 16989 - 21 = 16987 is a prime.

It is a super-2 number, since 2×169892 = 577252242, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16981) 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, 384 + ... + 425.

It is an arithmetic number, because the mean of its divisors is an integer number (3240).

216989 is an apocalyptic number.

It is an amenable number.

16989 is a deficient number, since it is larger than the sum of its proper divisors (8931).

16989 is an equidigital number, since it uses as much as digits as its factorization.

16989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819.

The product of its digits is 3888, while the sum is 33.

The square root of 16989 is about 130.3418582037. The cubic root of 16989 is about 25.7072688085.

The spelling of 16989 in words is "sixteen thousand, nine hundred eighty-nine".

Divisors: 1 3 7 21 809 2427 5663 16989