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4781 = 7683
BaseRepresentation
bin1001010101101
320120002
41022231
5123111
634045
716640
oct11255
96502
104781
113657
122925
13223a
141a57
15163b
hex12ad

4781 has 4 divisors (see below), whose sum is σ = 5472. Its totient is φ = 4092.

The previous prime is 4759. The next prime is 4783. The reversal of 4781 is 1874.

It is a happy number.

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: 1874 = 2937.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-4781 is a prime.

It is a super-2 number, since 2×47812 = 45715922, which contains 22 as substring.

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

It is a Duffinian number.

It is a plaindrome in base 8, base 13 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4783) 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 3 ways as a sum of consecutive naturals, for example, 335 + ... + 348.

It is an arithmetic number, because the mean of its divisors is an integer number (1368).

24781 is an apocalyptic number.

It is an amenable number.

4781 is a deficient number, since it is larger than the sum of its proper divisors (691).

4781 is an equidigital number, since it uses as much as digits as its factorization.

4781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 690.

The product of its digits is 224, while the sum is 20.

The square root of 4781 is about 69.1447756523. The cubic root of 4781 is about 16.8463666232.

Subtracting from 4781 its sum of digits (20), we obtain a square (4761 = 692).

Adding to 4781 its product of digits (224), we get a palindrome (5005).

It can be divided in two parts, 47 and 81, that added together give a 7-th power (128 = 27).

The spelling of 4781 in words is "four thousand, seven hundred eighty-one".

Divisors: 1 7 683 4781