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30505 = 56101

30505 has 4 divisors (see below), whose sum is σ = 36612. Its totient is φ = 24400.

The previous prime is 30497. The next prime is 30509. The reversal of 30505 is 50503.

It can be divided in two parts, 30 and 505, that added together give a palindrome (535).

30505 = 1232 + 1242.

30505 is nontrivially palindromic in base 9.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15129 + 15376 = 123^2 + 124^2 .

It is not a de Polignac number, because 30505 - 23 = 30497 is a prime.

It is a Smith number, since the sum of its digits (13) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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

It is a Duffinian number.

30505 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (30509) 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, 3046 + ... + 3055.

It is an arithmetic number, because the mean of its divisors is an integer number (9153).

230505 is an apocalyptic number.

30505 is the 124-th centered square number.

It is an amenable number.

30505 is a deficient number, since it is larger than the sum of its proper divisors (6107).

30505 is an equidigital number, since it uses as much as digits as its factorization.

30505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6106.

The product of its (nonzero) digits is 75, while the sum is 13.

The square root of 30505 is about 174.6568063375. The cubic root of 30505 is about 31.2457060767.

The spelling of 30505 in words is "thirty thousand, five hundred five".

Divisors: 1 5 6101 30505