13123505 has 4 divisors (see below), whose sum is σ = 15748212. Its totient is φ = 10498800.

The previous prime is 13123463. The next prime is 13123529. The reversal of 13123505 is 50532131.

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 6031936 + 7091569 = 2456^2 + 2663^2 .

It is not a de Polignac number, because 13123505 - 2⁶ = 13123441 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1312346 + ... + 1312355.

It is an arithmetic number, because the mean of its divisors is an integer number (3937053).

Almost surely, 2^13123505 is an apocalyptic number.

It is an amenable number.

13123505 is a deficient number, since it is larger than the sum of its proper divisors (2624707).

13123505 is an equidigital number, since it uses as much as digits as its factorization.

13123505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2624706.

The product of its (nonzero) digits is 450, while the sum is 20.

The square root of 13123505 is about 3622.6378510693. The cubic root of 13123505 is about 235.8757425456.

Adding to 13123505 its reverse (50532131), we get a palindrome (63655636).

The spelling of 13123505 in words is "thirteen million, one hundred twenty-three thousand, five hundred five".