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989 = 2343

989 has 4 divisors (see below), whose sum is σ = 1056. Its totient is φ = 924.

The previous prime is 983. The next prime is 991.

It is a happy number.

989 is nontrivially palindromic in base 10.

989 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 989 - 28 = 733 is a prime.

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

It is a Duffinian number.

989 is an undulating number in base 10.

It is a Curzon number.

It is a plaindrome in base 15 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (983) 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, 2 + ... + 44.

It is an arithmetic number, because the mean of its divisors is an integer number (264).

It is an amenable number.

989 is a deficient number, since it is larger than the sum of its proper divisors (67).

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

989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66.

The product of its digits is 648, while the sum is 26.

The square root of 989 is about 31.4483703870. The cubic root of 989 is about 9.9631980612.

The spelling of 989 in words is "nine hundred eighty-nine", and thus it is an aban number and an oban number.

Divisors: 1 23 43 989