12781085 has 4 divisors (see below), whose sum is σ = 15337308. Its totient is φ = 10224864.

The previous prime is 12781081. The next prime is 12781103. The reversal of 12781085 is 58018721.

It is a happy number.

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 7300804 + 5480281 = 2702^2 + 2341^2 .

It is a cyclic number.

It is not a de Polignac number, because 12781085 - 2² = 12781081 is a prime.

It is a super-5 number, since 5×12781085⁵ (a number of 37 digits) contains 55555 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12781081) 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, 1278104 + ... + 1278113.

It is an arithmetic number, because the mean of its divisors is an integer number (3834327).

Almost surely, 2^12781085 is an apocalyptic number.

It is an amenable number.

12781085 is a deficient number, since it is larger than the sum of its proper divisors (2556223).

12781085 is an equidigital number, since it uses as much as digits as its factorization.

12781085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2556222.

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 12781085 is about 3575.0643350855. The cubic root of 12781085 is about 233.8061376793.

The spelling of 12781085 in words is "twelve million, seven hundred eighty-one thousand, eighty-five".