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7989 = 32663
BaseRepresentation
bin1111100110101
3101221220
41330311
5223424
6100553
732202
oct17465
911856
107989
116003
124759
133837
142ca9
152579
hex1f35

7989 has 4 divisors (see below), whose sum is σ = 10656. Its totient is φ = 5324.

The previous prime is 7963. The next prime is 7993. The reversal of 7989 is 9897.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9897 = 33299.

It is a cyclic number.

It is not a de Polignac number, because 7989 - 29 = 7477 is a prime.

It is a D-number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7919) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1329 + ... + 1334.

It is an arithmetic number, because the mean of its divisors is an integer number (2664).

27989 is an apocalyptic number.

It is an amenable number.

7989 is a deficient number, since it is larger than the sum of its proper divisors (2667).

7989 is a wasteful number, since it uses less digits than its factorization.

7989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2666.

The product of its digits is 4536, while the sum is 33.

The square root of 7989 is about 89.3812060782. The cubic root of 7989 is about 19.9908291287.

The spelling of 7989 in words is "seven thousand, nine hundred eighty-nine".

Divisors: 1 3 2663 7989