12825781 has 4 divisors (see below), whose sum is σ = 12833100. Its totient is φ = 12818464.

The previous prime is 12825773. The next prime is 12825809. The reversal of 12825781 is 18752821.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 5803281 + 7022500 = 2409^2 + 2650^2 .

It is a cyclic number.

It is not a de Polignac number, because 12825781 - 2³ = 12825773 is a prime.

It is a super-2 number, since 2×12825781² = 329001316519922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12825181) by changing a digit.

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, 705 + ... + 5113.

It is an arithmetic number, because the mean of its divisors is an integer number (3208275).

Almost surely, 2^12825781 is an apocalyptic number.

It is an amenable number.

12825781 is a deficient number, since it is larger than the sum of its proper divisors (7319).

12825781 is an equidigital number, since it uses as much as digits as its factorization.

12825781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7318.

The product of its digits is 8960, while the sum is 34.

The square root of 12825781 is about 3581.3099558681. The cubic root of 12825781 is about 234.0783639455.

The spelling of 12825781 in words is "twelve million, eight hundred twenty-five thousand, seven hundred eighty-one".