12780817 has 12 divisors (see below), whose sum is σ = 15026340. Its totient is φ = 10838016.

The previous prime is 12780809. The next prime is 12780827. The reversal of 12780817 is 71808721.

It can be written as a sum of positive squares in 2 ways, for example, as 2547216 + 10233601 = 1596^2 + 3199^2 .

It is not a de Polignac number, because 12780817 - 2³ = 12780809 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12780827) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3409 + ... + 6097.

It is an arithmetic number, because the mean of its divisors is an integer number (1252195).

Almost surely, 2^12780817 is an apocalyptic number.

It is an amenable number.

12780817 is a deficient number, since it is larger than the sum of its proper divisors (2245523).

12780817 is an equidigital number, since it uses as much as digits as its factorization.

12780817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2800 (or 2793 counting only the distinct ones).

The product of its (nonzero) digits is 6272, while the sum is 34.

The square root of 12780817 is about 3575.0268530460. The cubic root of 12780817 is about 233.8045034810.

The spelling of 12780817 in words is "twelve million, seven hundred eighty thousand, eight hundred seventeen".